As Xykon casts Burning Hands, two things happen in immediate succession.

First, the shelves suddenly glow with arcane energy. Evangeline? Good luck getting through the glowing force that is now covering them - and which neatly reflects some of the fire from Xykon's spell, sending it around some corners.

Second, and perhaps more obviously (somehow), a very loud alarm goes off.

"DAMN IT!"

Immediately, a goblin with a distinctive red cloak and a holy symbol around his throat bolted into view.

"... Oh, great. Intruders."