After you've done this you have to examine the two pools in the room
Return to the Shade of Bylze ( 12, 157, -40 ) /waypoint 12, 157, -40 for your reward and a very revealing twist regarding the shade's true identity.
NOTE: You will need the Disk of Bylze to respawn the shade. If you destroyed it you will need to return and reopen the chest that dropped it in the quest Burglars Afoot. Location of the chest is in Tenebrous Tangle ( 563, -147, 641 ) /waypoint 563, -147, 641. Just inspect the chest to get a new one.