As the veilfire lights up the room, something glints on one of the walls. And, like an easily distracted animal, Strange moves over to inspect it. It's a veilfire rune of some kind.

"Bring the torch over here!" Strange yells, gesturing for Solas to come near him. "I need more light if I am to read the rune."

Unfortunately, that yelling's loud enough that further back in the temple, something big and nasty and murdery becomes aware of their presence.