The alchemist Walker (my screenshot) and the poetry loving mage Kistandalius are not the same. You're right about the mage - he only leaves the shop during this poem. Rush into his back room, loot the chest and grab the book.
The chest in his shop room can be looted afterwards: Just turn into a spider <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />. This works <img src="/ubbthreads/images/graemlins/biggrin.gif" alt="" />. Though you can't enter his back room anymore.
Kiya
