The sequel to The Victorian Ladies’ Detective Collective, Breaking Out of Bedlam, will feature a locked room mystery … specifically, a woman disappears from a locked room. According to John Dickson Carr, a master of the genre, there are seven solutions to a locked room murder. Robert Adey expanded Carr’s list considerably.
In his book Locked Room Murders. Adey identifies the following twenty possible solutions:
1. Accident
2. Suicide
3. Remote control – the use of poison gas or the victim is impelled to kill themselves inadvertently
4. Mechanical or other devices
5. An animal carries out the murder
6. An outside intervention is made to appear as if the murder has taken place by a murderer inside the locked room, e.g. by throwing a dagger through a window at the victim from outside the room
7. The victim has been killed earlier but is made to appear as if they were alive at a later point
8. The victim is presumed to be dead but is in fact killed later than believed, e.g. by first person to enter the room
9. The victim is wounded outside the locked room but enters, locks the room and dies inside
10. The key, bolt or catch securing the door is manipulated from the outside, using pliers, string or some other device, to lock the door after the murderer has exited
11. The door or window of the room is unhinged and removed to gain entry and the murderer then replaces it after committing the crime
12. As above but confining the removal to a window pane
13. Entry to the room is gained by some acrobatic maneuvre
14. The door is locked or wedged from the outside and the key is only replaced on the inside after entry to the room by those who find the body
15. As above but the key is returned into the room before everyone enters to discover the body
16. Other methods of gimmicking the door or windows
17. The murderer enters and exits through a secret panel or uses one to enable the weapon to be propelled at the victim
18. The murderer is in the room all the time
19. The murderer is provided with an alibi for the critical time when the murder is committed
20. Other impersonation stunts
Since the woman in my play disappears, vs. being murdered, it will be a little bit different, but these twenty solutions will help me plot, nevertheless!
Door lock image by Omar González from Pixabay