Assuming you fast travel back to the Priory, you'll arrive in chaos. Eronor comes running at you, and swiftly explains what's happened and what's still happening. Maborel Dead, and the priory under assualt.

Be sure to kill the assassins asap since not doing so, can result in the death of important characters. Kill first the attacked coming at you, then the two behind the priory, and together with brother Piner and Martin go into the chapel to save the life of Jauffre.

Be sure to keep the last two alive as with their deaths, the MQ will be over.

Once you've saved them, follow Jauffre to find the amulet of kings has been stolen and listen to some more talk before Jauffre mentions the next stop; Cloud ruler temple, an Ancient blades fortress to the north of Bruma.

Either fast travel there, or take the horses behind the priory, personally I recommend fast travelling as the horse method didn't exactly go smooth for me ^_^.

Once in cloud ruler temple, speak to Jauffre to get the opportunity to join the blades, doing so will give you a free set of armor and nice weapons, and then he and Martin, after asking them about it will explain yet more of what's to come.