Horrorstör is a 2014 horror comedy novel written by Grady Hendrix and illustrated by Michael Rogalski. The novel is set in ORSK, an IKEA-like store, where a group of employees - including store manager Basil and employees Amy and Ruth Anne - stay overnight to investigate strange supernatural occurrences. The story follows Amy, who is unhappy with her job at ORSK. As the group investigates the store, they discover that the land was previously the site of a prison with a cruel warden named Worth. The ghosts of the prisoners, known as “penitents”, haunt the store and try to capture the employees. Amy and Basil manage to escape the store before it floods, but the other employees are not so lucky. In the end, a new store called Planet Baby is built on the site, and Amy and Basil vow to rescue the remaining employees trapped inside.

https://www.goodreads.com/book/show/13129925-horrorst-r