Well, depending on your choice this can be one of the longest or one of the shortest quests in the main quest. It's suggested to you that you get the aid of the other cities in Cyrodiil to help defend Bruma while you carry out another part of Martin's plan.
However if you're confident that you don't need the help of others, or pherhaps not the help of everyone, then you could go along with the quest and simply start it right now.
I'll assume however that you, like me, will get the help of the other cities.
One note, there's no sense in going to the Imperial city for this, they won't help you no matter what.
Speak to countess Milona Umbranox in the castle here. She'll ask you to close the gate located to the northwest of the city.
Upon entering the gate, you find yourself once again in enemy territory, This time you won't be able to simply walk up to the citadel, instead there are two caves connecting you to the upper part and the Citadel.
Two caves with rather different ways to get there, unless you wish to enter another puzzle, I recommend the cave closest by. That is from the entrace gate, turn left and then almost immediately right, a small bit up the mountain. Fight past some daedra in there and you wind up close near the entrance of the Citadel.
From the acces of this cave, walk a small bit counter clockwise and you'll find yourself at the entrance of the Citadel.
Once inside, no catches. Simply fight past all the daedra to the upper levels and once there touch the sigil stone to close the gate and be transported back to Anvil.
Speak to the countess again and she'll give you her support. On to the next city now.
Speak to count Regulus Terentius here, He'll ask you to locate and close the gate located to the northwest of the city. (Be sure not to make the same mistake I did, that is closing the wrong gate and then thinking the game has glitched ;-) )
Upon entering Oblivion here, head south and then east. Be carefull of the turrets there though, but east is the way to go as you can open a gate by activating switch at the top of the shrine there.
After opening the gate, either return to where you came into the world and go north through the now open gate into the citadel, or head a bit further north from the shrine and then turn west to enter the very same citadel.
Once inside, same old same old. Fight your way upwards and touch the sigil stone.
Here the situation becomes a tad more complicated, still speak to the Count to get the quest to close the gate, but the complication arises when you speak to the guards just outside the Gate.
They'll mention the son of the count was trying to show off, and entered the gate together with a friend. So now not only are you expected to close the gate, but also to save the life of the son of the count.Though don't worry, even with a dead count's son you'll be able to complete this quest. The reward however will be less good.
But don't worry, looking for the son won't inconvenience you too much, in fact he'll be waiting for you right along the route you need to take to the Citadel anyway.
Head due east towards the citadel and you'll notice a few friends of the count's son lying dead. Apparently their mission wasn't as much a success as they thought it would be. Just before getting to the bridge leading to the citadel, you'll meet the only two survivors, the count's son and a friend of his.
After finding them, they'll play as backup untill they're either killed or untill you close the gate. Speaking to the son also triggers the gates across the bridges to open btw.
Cross the bridge, enter the citadel, watch for those nasty spike and blade traps again and fight your way upwards all the while keeping the son alive, and you're done. Take the sigil stone, thus closing the gate and you wind up just outside Cheydinhal again.
Speak to the son to be given an honorary position in his organisation, the knights of the thorn. Then speak to the count again to finish the quest.
Assuming you kept the son alive, you'll also be rewarded with the choice of a unique artifact, either a sword with desintegrate armor enchantment or a staff with a damage strength and shock enchantment.
You'll of course also receive the count's aid for the overall quest.
Speak to countess Arriana Valga here to get the quest. The gate is located to the south of the gate of Chorrol.
Upon entering the gate, you'll notice two citadels, one right next to you and another one due south. The one next to you has some great loot, but isn't your goal here.
You'll notice the center Citadel is surrounded by 5 smaller towers, you'll need to go through at least one of those to reach the central tower. Enter the central tower, and Fight your way upwards, you'll find yourself unable to go any higher.
The key to this mystery are the other towers. Going through one of them, will allow you to get higher up on the main citadel. Once higher in the citadel, the story becomes the same again. Fight your way past traps and daedra to get to the Sigil stone, collect it and close the gate.
Report back to the countess and she'll agree to send aid to Bruma.
Rather then needing to close a gate here, you already did that, here you're expected to help free the castle. Apparently that's still held by the Daedra and that's where you come in.
Travel to the chapel at Kvatch there and speak to captain Savlian Matius. He'll ask you to come along with liberating the castle, agree and he'll lead the way out the eastern chapel doors. You'll come across some Daedra there, the way to the castle is very short but also blocked, that is the gate leading to the actual castle is blocked.
If you have either bow and arrow, or some spells, try and take out the daedra atop the castle walls. That makes walking and running around that area a lot easier.
Speak to the captain once again and he'll give you a solution to the locked gate problem, a secret route leading to the inside of the castle's gatehouse. First things first however, the key. travel back to the chapel and speak to private Berich Inian. He has the key and being polite to him will also get him to explain the route you need to take to get to the secret passageway. The private will follow you along, and speak to the other soldiers in the chapel will get you a few more helpers.
Follow the route leading you through the crypt, onto the underground way into the castle. Be prepared to face a number of daedra guarding the way. Follow the entire path and at the end you'll find yourself in the gatehouse of the castle, with two gates and one lever. Activate the lever, and assuming the soldiers that went with you are still alive, you'll have both them and the soldiers with captain Savlian to wipe out the daedra in the courtyard, and later inside the castle itself. With all those soldiers that shouldn't cause a problem.
Once you've found the body of the late count of Kvatch, and given his signet ring to Savlian, the captain will agree to aid Bruma.
Speak to count Marius Caro here for this quest. The gate is located to the northeast of the city.
Enter the gate to find yourself on a small island across the way from the main citadel. Travel a small way west to find a cave leading to the main island. Fight your way through it and arrive on the main island.
Your first goal should be to enter the main citadel, it cannot be reached through normal means. You'll have to go through the smaller towers to open the gates blocking the entrance to the Citadel. It's not that hard, except for the Daedra you might encounter.
Once inside the main citadel, it's back to business as usual as you'll have to fight through daedra, avoid traps and find the sigil stone.
Find it, close the gate, return to the vastle and speak to the count to get his support for the Bruma struggle.
Another difference here, speak not to the count at first, but to one of his stewards, Mercator Hosidus (unless you killed him during the mages guild quests) or the argonian Hal-liurz.
Speak to them and explain the situation, and they'll set up a meeting with the count.
You might think this odd? The count is a vampire so he doesn't show himself too often lest he be detected.
Speak to the count to hear the same story you've heard before, close the gate for support. The gate is located to east of castle Skingrad.
Once inside you'll see two smaller towers and a large third tower which is across a pool of lava. Your first step is the two smaller towers, at the top you'll find switches that will activate a bridge across the lava, leading to the actual Sigil tower.
It's basically fighting your way past daedra again, activating the switches, in the main tower it's the same, fight your way up and touch the sigil stone to close the gate of oblivion and re appear near Skingrad.
Return back to the count, report your success and he'll agree to aid Bruma.
Once you have the support of all various cities, you can head back to cloud ruler temple and report your success to Jauffre.
Speak to Martin to start the actual quest here. He'll tell you to contact the countess and set up a meeting in the chapel of Bruma. Speak to her and be prepared, getting her to the chapel means you're almost going to war so make sure you're prepared.
Inside the chapel, the countess will speak to Jauffre and Martin and then will wait for your final go ahead before starrting everything.
Travel together with martin, Jauffre and some blades to the gate of bruma and you'll be cheered by folks in the streets, or rather Martin will be, and you can observe that.
Provided you got the aid of all other cities, just outside the gate you'll be greeted by 10 warriors ready to aid you in the defence of Bruma. Follow martin to the site of the impending war and defend him, yourself and the others as a total of 4 oblivion gates open.
I found that with all the help of all the cities, I could even stand by and do nothing while they take care of everything, so your real task here doesn't start untill the great oblivion gate opens in the center of that small valley.
As soon as it opens, and when you're sure nothing bad will happen to your companions, head inside as soon as possible.
Why asap? Because this is one of few quests in oblivion that has a time limit. Once inside the gate you'll immeditately notice a large daedric machine "crawling" towards the oblivion gate. Your task should be to take the great sigil stone before that machine get's all the way through the gate.
Impossible? no, but it is hard. So be swift here; enter the first tower on the left. Go to the top and follow the bridge leading to the tower further along. travel down here and exit on the other side to find yourself nearly past the daedric machine. Run along following the path there and before you you should see two more small towers and a large Citadel, enter the tower on the left as it's closest.
Again go to the top as soon as possible and flip the switch that will open the gate blocking your access to the main citadel.
Pass through the gate, enter the main citadel and fight your way past two sigil keepers, daedra and traps to get to the sigil room and take the stone.
Once you have it, that's it. An end to the rushing, now you can relax for a bit as Martin congratulates you and such.
However if you're confident that you don't need the help of others, or pherhaps not the help of everyone, then you could go along with the quest and simply start it right now.
I'll assume however that you, like me, will get the help of the other cities.
One note, there's no sense in going to the Imperial city for this, they won't help you no matter what.
Anvil
Speak to countess Milona Umbranox in the castle here. She'll ask you to close the gate located to the northwest of the city.
Upon entering the gate, you find yourself once again in enemy territory, This time you won't be able to simply walk up to the citadel, instead there are two caves connecting you to the upper part and the Citadel.
Two caves with rather different ways to get there, unless you wish to enter another puzzle, I recommend the cave closest by. That is from the entrace gate, turn left and then almost immediately right, a small bit up the mountain. Fight past some daedra in there and you wind up close near the entrance of the Citadel.
From the acces of this cave, walk a small bit counter clockwise and you'll find yourself at the entrance of the Citadel.
Once inside, no catches. Simply fight past all the daedra to the upper levels and once there touch the sigil stone to close the gate and be transported back to Anvil.
Speak to the countess again and she'll give you her support. On to the next city now.
Bravil
Speak to count Regulus Terentius here, He'll ask you to locate and close the gate located to the northwest of the city. (Be sure not to make the same mistake I did, that is closing the wrong gate and then thinking the game has glitched ;-) )
Upon entering Oblivion here, head south and then east. Be carefull of the turrets there though, but east is the way to go as you can open a gate by activating switch at the top of the shrine there.
After opening the gate, either return to where you came into the world and go north through the now open gate into the citadel, or head a bit further north from the shrine and then turn west to enter the very same citadel.
Once inside, same old same old. Fight your way upwards and touch the sigil stone.
Cheydinhal
Here the situation becomes a tad more complicated, still speak to the Count to get the quest to close the gate, but the complication arises when you speak to the guards just outside the Gate.
They'll mention the son of the count was trying to show off, and entered the gate together with a friend. So now not only are you expected to close the gate, but also to save the life of the son of the count.Though don't worry, even with a dead count's son you'll be able to complete this quest. The reward however will be less good.
But don't worry, looking for the son won't inconvenience you too much, in fact he'll be waiting for you right along the route you need to take to the Citadel anyway.
Head due east towards the citadel and you'll notice a few friends of the count's son lying dead. Apparently their mission wasn't as much a success as they thought it would be. Just before getting to the bridge leading to the citadel, you'll meet the only two survivors, the count's son and a friend of his.
After finding them, they'll play as backup untill they're either killed or untill you close the gate. Speaking to the son also triggers the gates across the bridges to open btw.
Cross the bridge, enter the citadel, watch for those nasty spike and blade traps again and fight your way upwards all the while keeping the son alive, and you're done. Take the sigil stone, thus closing the gate and you wind up just outside Cheydinhal again.
Speak to the son to be given an honorary position in his organisation, the knights of the thorn. Then speak to the count again to finish the quest.
Assuming you kept the son alive, you'll also be rewarded with the choice of a unique artifact, either a sword with desintegrate armor enchantment or a staff with a damage strength and shock enchantment.
You'll of course also receive the count's aid for the overall quest.
Chorrol
Speak to countess Arriana Valga here to get the quest. The gate is located to the south of the gate of Chorrol.
Upon entering the gate, you'll notice two citadels, one right next to you and another one due south. The one next to you has some great loot, but isn't your goal here.
You'll notice the center Citadel is surrounded by 5 smaller towers, you'll need to go through at least one of those to reach the central tower. Enter the central tower, and Fight your way upwards, you'll find yourself unable to go any higher.
The key to this mystery are the other towers. Going through one of them, will allow you to get higher up on the main citadel. Once higher in the citadel, the story becomes the same again. Fight your way past traps and daedra to get to the Sigil stone, collect it and close the gate.
Report back to the countess and she'll agree to send aid to Bruma.
Kvatch
Rather then needing to close a gate here, you already did that, here you're expected to help free the castle. Apparently that's still held by the Daedra and that's where you come in.
Travel to the chapel at Kvatch there and speak to captain Savlian Matius. He'll ask you to come along with liberating the castle, agree and he'll lead the way out the eastern chapel doors. You'll come across some Daedra there, the way to the castle is very short but also blocked, that is the gate leading to the actual castle is blocked.
If you have either bow and arrow, or some spells, try and take out the daedra atop the castle walls. That makes walking and running around that area a lot easier.
Speak to the captain once again and he'll give you a solution to the locked gate problem, a secret route leading to the inside of the castle's gatehouse. First things first however, the key. travel back to the chapel and speak to private Berich Inian. He has the key and being polite to him will also get him to explain the route you need to take to get to the secret passageway. The private will follow you along, and speak to the other soldiers in the chapel will get you a few more helpers.
Follow the route leading you through the crypt, onto the underground way into the castle. Be prepared to face a number of daedra guarding the way. Follow the entire path and at the end you'll find yourself in the gatehouse of the castle, with two gates and one lever. Activate the lever, and assuming the soldiers that went with you are still alive, you'll have both them and the soldiers with captain Savlian to wipe out the daedra in the courtyard, and later inside the castle itself. With all those soldiers that shouldn't cause a problem.
Once you've found the body of the late count of Kvatch, and given his signet ring to Savlian, the captain will agree to aid Bruma.
Leyawiin
Speak to count Marius Caro here for this quest. The gate is located to the northeast of the city.
Enter the gate to find yourself on a small island across the way from the main citadel. Travel a small way west to find a cave leading to the main island. Fight your way through it and arrive on the main island.
Your first goal should be to enter the main citadel, it cannot be reached through normal means. You'll have to go through the smaller towers to open the gates blocking the entrance to the Citadel. It's not that hard, except for the Daedra you might encounter.
Once inside the main citadel, it's back to business as usual as you'll have to fight through daedra, avoid traps and find the sigil stone.
Find it, close the gate, return to the vastle and speak to the count to get his support for the Bruma struggle.
Skingrad
Another difference here, speak not to the count at first, but to one of his stewards, Mercator Hosidus (unless you killed him during the mages guild quests) or the argonian Hal-liurz.
Speak to them and explain the situation, and they'll set up a meeting with the count.
You might think this odd? The count is a vampire so he doesn't show himself too often lest he be detected.
Speak to the count to hear the same story you've heard before, close the gate for support. The gate is located to east of castle Skingrad.
Once inside you'll see two smaller towers and a large third tower which is across a pool of lava. Your first step is the two smaller towers, at the top you'll find switches that will activate a bridge across the lava, leading to the actual Sigil tower.
It's basically fighting your way past daedra again, activating the switches, in the main tower it's the same, fight your way up and touch the sigil stone to close the gate of oblivion and re appear near Skingrad.
Return back to the count, report your success and he'll agree to aid Bruma.
Bruma Gate
Once you have the support of all various cities, you can head back to cloud ruler temple and report your success to Jauffre.
Speak to Martin to start the actual quest here. He'll tell you to contact the countess and set up a meeting in the chapel of Bruma. Speak to her and be prepared, getting her to the chapel means you're almost going to war so make sure you're prepared.
Inside the chapel, the countess will speak to Jauffre and Martin and then will wait for your final go ahead before starrting everything.
Travel together with martin, Jauffre and some blades to the gate of bruma and you'll be cheered by folks in the streets, or rather Martin will be, and you can observe that.
Provided you got the aid of all other cities, just outside the gate you'll be greeted by 10 warriors ready to aid you in the defence of Bruma. Follow martin to the site of the impending war and defend him, yourself and the others as a total of 4 oblivion gates open.
I found that with all the help of all the cities, I could even stand by and do nothing while they take care of everything, so your real task here doesn't start untill the great oblivion gate opens in the center of that small valley.
As soon as it opens, and when you're sure nothing bad will happen to your companions, head inside as soon as possible.
Why asap? Because this is one of few quests in oblivion that has a time limit. Once inside the gate you'll immeditately notice a large daedric machine "crawling" towards the oblivion gate. Your task should be to take the great sigil stone before that machine get's all the way through the gate.
Impossible? no, but it is hard. So be swift here; enter the first tower on the left. Go to the top and follow the bridge leading to the tower further along. travel down here and exit on the other side to find yourself nearly past the daedric machine. Run along following the path there and before you you should see two more small towers and a large Citadel, enter the tower on the left as it's closest.
Again go to the top as soon as possible and flip the switch that will open the gate blocking your access to the main citadel.
Pass through the gate, enter the main citadel and fight your way past two sigil keepers, daedra and traps to get to the sigil room and take the stone.
Once you have it, that's it. An end to the rushing, now you can relax for a bit as Martin congratulates you and such.