Zazzie

Im playing through Watcher's Keep with Irenicous in the party right now and i found the deva in the third level who wanted me to help him, but i can't seem to find the demon that stole the spark anywhere. I found one of the items next to the mad elf and another after i played cards with the demon in the end of the third level but im stuck now

Do the quest continue on the next level or have i missed anything?
The deva doesn't seem to live very long after you pick it up either so if it does i will have some trubble keeping it alive long enough.

Could you offer some help please?