Investigate the Alchemist Shop

Algernon's alchemist shop in the Apothecarium is the locus of a strange disturbance. Invisible creatures, made solely of magic, wander the shop--there must be a reason, and we must find it!$B$BInvestigate the disturbance and capture those creatures. Take a chest of coffers and a scroll from behind me. Use the scroll at the shop to make the creatures visible, subdue them with your spells, then throw down a coffer to capture them. Return with the filled coffers, the empty coffers and the cantation.