context: Dr. Rod Barrett's (William Prince) young daughter has been kidnapped by a mysterious maniac who has buried her alive "in a large coffin". The doctor has five hours in which to find and rescue her before her air runs out and she suffocates. The maniacal killer apparently also murdered Barrett's wife and her sister.
  Various family members and friends become potential suspects as they help in the search, wandering through dark graveyards, crypts, thunder and lightning, and red-herrings. The somewhat muddy plot leads to a surprise conclusion that reveals the guilty party and the motive. At the film's end, a narrator requests that the audience not reveal the unexpected ending to others.[citation needed]
question: What room does Astrid lock herself in?
answer: In the guest room