A review by erine
Behind the Bookcase by Mark Steensland, Kelly Murphy

Basically this reads as a detailed testimonial for why you should always have a death plan. Sarah's Grandma Winnie dies without one, and it throws multiple worlds into chaos, unleashes a very passive army of the dead, as well as setting up events to allow a vindictive dictator access to the ordinary world. So basically, make sure you talk early and often with your friends, family, and heirs about what should happen if you die.

Also: horrific transformations as punishment, questing adventures to multiple worlds, sibling rivalry, etc.