Idea for a locked room murder mystery.

Miscellaneous and Personal Stuff I Must Share
1

I’ve always had a fondness for old fashioned murder mystery stories. My favourite sub genre is the ‘locked room’ mystery. You know the thing. The victim is found murdered in a locked room with the key in his pocket, and the killer has seemingly vanished in a puff of smoke and you have to work out how he did it, as well as who he is.

Anyway, I work shifts (three weeks days, one week nights) and on the night shift, there’s not much to do except read, surf the net, and think about stuff, and today I had an idea for a locked room mystery which (as far as I know) hasn’t been done before. Here’s the set-up. Tell me what you think.

So, it’s set in the 1930s or 40s and the victim is this rich Uncle Pennybags type who has made a lot of enemies in his business dealings over the years and has recently been speculating about changing the beneficiaries of his absurdly enormous will. He lives in a big fancy mansion just like the one in every old murder mystery ever, and on the day of the crime, his house is full of family and business associates, all of whom have a reason to do him in. The last time he is seen alive is when he goes into his study to take a call on his private phone from his solicitor to discuss the aforementioned will and, due to the delicate nature of the call, he locks the door behind him.

About an hour later, there’s a big old kerfuffle in the study. Shouting, furniture being knocked about, “HELP! HELP!”, you know the drill. A few people in nearby rooms rush out and find the door locked. One of them grabs a spare key and unlocks the door but it still won’t open. The old man’s bolted the door as well. Anyway, they knock the door down and find the room in disarray, and Pennybags sat behind his desk with a big old samurai sword sticking out of his chest and a very annoyed look on his face. One of them calls the police from the study phone while the others look behind the curtains, under the desk, inside the old man’s magnificent ornate weapons chest that he brought home from the orient as a souvenir (because, like any self-respecting old Colonial, he obviously has one of those) and anywhere else a murderer might be hiding, and they don’t find anyone. The windows are locked, and, when the police arrive, they find the key in the old man’s pocket. Curiously, further investigation shows that, even though the caller identified himself to the family butler as the old man’s solicitor, the telephone company can’t find any record of a call made from the solicitor’s office on the day of the murder.

So…whodunnit?

The answer is…well, who cares? It could be anyone. The important thing is how he did it. The murderer had a simple, ten step plan.

  1. Step 1: Phone the study from any other phone in the house (remember, the study phone is on its own private line) and pretend to be the lawyer. Wait for the Butler to answer it and then wait for him to leave to summon the old man. This is just to get the old man in the study.

  2. Step 2: Put the phone down and, while the study is empty, sneak in and hide in the weapons chest. Incidentally, the chest is behind the desk. Probably should’ve mentioned that.

  3. Step 3: Wait until the old man has arrived and locked the door behind him, and then kill him, ninja style, with the big old samurai sword in the weapons chest.

  4. Step 4: Quietly dismantle the room. Turn the chairs over, scatter the papers on the desk, take the books off the shelves and place them on the floor, that kind of thing.

  5. Step 5: Unlock the study door from the inside and put the key in the old man’s pocket.

  6. Step 6: Replace the wooden bolt with an identically shaped metal bolt.

  7. Step 7: Put a record on the gramophone. This is a specially made record which is 30 minutes of absolute silence, and 30 seconds of a pre-recorded struggle.

  8. Step 8: Check the coast is clear, sneak out. Lock the door from the outside with a duplicate copy of the key and then use a very strong magnet to draw the bolt into place through the door from the outside. Snap the wooden bolt in half.

  9. Go away, meet someone nearby and establish an alibi. Wait for the record to play the “struggle” and wait to be summoned by whomever gets to the door first.

  10. After knocking down the door, tell everyone else who happens to be there to check to see if the murderer is still in the room and, while they’re distracted, steal the metal bolt and throw the broken wooden bolt on the floor.

And there you have it. Now, bear in mind I’m terrifically sleep deprived at the minute so there could be a billion reasons why this idea is totally stupid, but if they exist I can’t see them in my present state. My two questions are:

  1. Does it make sense (and I mean ‘Agatha Christie style murder mystery novel sense’, not ‘Homicide, life on the Streets’ sense.)?

  2. Has anyone done it before? I know recordings are a tried and tested way to establish alibis in murder mystery novels, but I can’t recall any where the killer lured the victim into his desired location in this manner, or used a magnet to lock the door from the outside. Have I actually come up with a (semi)-original idea?

By the way, if anyone wants to use this idea have at it. I’m never going to do anything with it. All I ask is a free autographed copy if you ever get it published :slight_smile:

2

I like it, though the recording seems to be the weak spot. Presumably the turntable would still be revolving and drawing attention to itself. The killer would have to, somehow, stop it without anyone noticing and get rid of the recording. I also think if the study phone is on a private line then records would show the call came from the other in-house line.

3

I like it, though I admit it reminds me a bit of the Columbo episode where the member of a thinly-disguised Mensa perches a book on a record player, and when the record ends (and everyone including the murderer are together somewhere else in the house) the book falls with a heavy thump, implying that’s when the victim died.

4

Why would the door have a wooden bolt in the first place? Leave out the complicated bolt switch and just have a metal bolt to begin with. You don’t need the recording either or the staged struggle. Eventually someone would have gone to check on ole Uncle Pennybags, become concerned and broken down the door.

5

The point of the complicated recording is to establish that the killer has an alibi because he’s with the others. Finding him eventually isn’t quite as airtight.

6

The killer also needs to be present when storming the room so he can hide important evidence. It’s easier when he knows exactly when that happens.

7

Two points:

  1. It would be highly unlikely for any household in the 1930s or 1940s to have two telephones, but if they did there would be records of the calls. There might well be a human switchboard operator.

  2. A “specially made record which is 30 minutes of absolute silence, and 30 seconds of a pre-recorded struggle.” This is a lot easier said than done.

a) There was no way to create a personal vinyl record at home. It required expensive and specialized equipment, which wasn’t normally available outside large commercial gramophone companies. Pressing records was a complicated technical process.

b) Playing time was short. 78rpm - about 3 minutes, 45 rpm - about 8 minutes, 33 1/3 ‘long playing’ records - about 30 minutes, but only introduced in 1948.

8

I agree. Better to set it in modern times (still in an old house) and the killer hides an mp3 player in back of the stereo to play the 30-minutes-plus-30-seconds recording. He can surreptitiously grab it later when the whole family storms the room.

9

Agatha Christie once had someone manage this sort of trick with

the playback from a dictation machine

10

The timing of the phone call stuff seems questionable.

  • where did the butler answer the private line? And why? Such lines were generally connected only to a single phone in the study, with no extensions where anyone could listen in. So the butler answered it in the study? Why would the butler be hanging around in the study when the house is full of guests all wanting services?

  • when did the murderer hang up the other phone extension that he had called on? He had to have set down the receiver and left it connected while the butler went to locate the victim and the murderer snuck into the room to hide. If the victim found the phone line dead and slammed it down again, breaking the connection, then soon the other received that the murderer had left off hook would start beeping with the phone companies loud off-hook warning tone. If the murderer killed the victim before he hung up the phone, the line is still open, so how can that phone be used to call the police?

  • And better hope nobody else in the house wanted to use the phone during this time. In a house full of relatives & business associates, what are the odds of that.

11

First, I’m not sure magnets are able to operate a bolt through a wooden door. Perhaps modern (rare earth) magnets can, but I’m not sure if they had those readily available back in the 1930’s or 1940’s. Perhaps an electromagnet might have worked, but I seriously doubt a hand-held magnet would have.

I just tried an experiment using a disk-drive magnet and a drill bit through two pieces of wood. The first one was the wooden folding table that I use for my desk. The wood is just a tiny bit over 1/2" thick. I put the magnet underneath the table and the drill bit on top. I could get the drill bit to roll easily, and was also (to my surprise, I might add), get it to move lengthwise, as would be necessary in your scenario. But, while it moved lengthwise, I am not sure it would be able to move if encased in a surrounding sleeve, or whatever it is that surrounds a bolt used for a door.

Then, I tried the same thing on the IKEA plank I use for my monitor stand, which is 1" thick. Using the same magnet and drill bit, I could make the drill bit roll, but had absolutely no lengthwise movement. Ergo, if the door was over an inch thick (and, really, in those old houses, weren’t the doors made of really thick oak?), then it would have to be a really strong magnet.

Second, do you realize how much stronger metal is than wood? It would be very difficult to break a bolt, as you have suggested. The bolt would bend and would not break unless it had been deliberately weakened at some point. Take a paper clip (which is far, far thinner than any door bolt) and try to snap it in half.

If you are really determined to use the magnet/metal bolt trick, you might consider making a replacement wooden bolt with a tiny metal rod at one end, such that the metal rod did not extend past the door opening. Then, the bolt could be moved from the other side and the discoverers would only be faced with breaking a wooden bolt, rather than trying to break a metal bolt.

12

The whole bolt thing seems over-complicated, too.

First, I’ve never heard of a wooden bolt. They’re always metal. So have it be metal in the first place, and forget the complication of replacing the wooden bolt temporarily & then switching them back later. (Also, usually bolts can’t be removed from the sleeve without unscrewing the whole assembly from the door to disassemble it.)

Second, when a door is broken down, usually the bolt hardware doesn’t break at all – either the screws holding it to the door pull out of the wooden door, or the wood of the door frame breaks. The bolt assembly itself is still intact.

Finally, a rich mans study in his mansion would not be defaced with an external bolt assembly, like the kind you use in a barn. It would have a nice looking dead-bolt lock builtin on the door, the kind that can only be locked/unlocked from the inside.

P.S. You’d better have the murderer shout “Nobody touch the body – leave it for the police!”, because if anyone touches the body, the temperature would make it clear that it’s been dead for an hour or more, not just seconds ago. Especially if the family doctor is present in the house (quite likely for such a gathering), and is called to make sure he’s actually dead. Better have something in the story telling how Uncle Pennybags has fought with the family doctor and forbidden him to enter his house.

13

There was an episode of Monk where this sort of happened in reverse. The victim was an actress who was once in a horror movie. Her husband added a clip of her fake death to an exercise tape she would watch. He then went outside where some TV crews were waiting (I don’t remember why). As he was talking to them, she started exercising, then everyone outside heard her screaming. He runs in, kills her, and then claims the killer escaped out the back door.