Speaking to Martin again, will have him tell you that he needs 4 items and with them, you'll be able to enter the paradise of Camoran and eventually kill him.

The first is a daedric artifact, any will do. If you don't already have one, I strongly recommend doing the quest for Azura's simply because it's so far the easiest I've done ;-).

Open the book modern heretics, lying on Martin's table and the location of this shrine will be marked on your map. Located straight north from the Lake Arrius caverns you visited earlier.

Travel there, I fast travelled to the caverns and then used my horse to travel due north, and you'll find a few will-o-the-wisp's near the shrine, kill them and keep at least one of their ingredients.

The wait untill the time is either 5-7 am or 5-7 pm and "activate" the statue of Azura. She'll give you her quest; find and kill 5 vampires. Travel due southeast to the Gutted mine (I encountered an oblivion gate just outside, so that might be a little detour for you ;-))

Enter the mine and the vampires shouldn't be too hard to locate inside. Be carefull though and try to take them out as soon as possible. As soon as they see you, they turn invisible and without a detect life spell or something similarly usefull, they're hard to find again.

Kill all five and report back to the stature for the end of this quest and her reward, Azura's soulgem. A reusable soulgem.

Now just my advice to do Azura's quest, you can do whichever one you want to do.

Travel back to cloud ruler temple, and speak to Martin to finish this quest and go on the second scavenger hunt.