Twistery #22 solution.

1 locked room containing 1 corpse. 1 barred window. Key was on the inside, still in the lock: a silvery blob on the end, the 1 clue.

It was a poky little room, a garret from another age, perched atop four twisting, crumbling flights of stairs. Climbing up to it, you had the sense that all there was in the world was that narrow stairway and the strange solitary room balanced on top of it. A lonely room, in other words, isolated even from the house that contained it.

On any ordinary day you would have been struck by the smell of mildew and dust in the air. Old-fashioned smells that took you back to a time before you were born.

But today another smell drove out all others. And there weren’t just motes of dust in the air. Big black flies buzzed and spun, drunk on the stench of death.

It was a lopsided room. A room of gaps and drafts. But no gap so large that a murderer could slip through.

The dead man’s life was there in the room. A single bed. A single chair. A single shelf with a single book. A primus stove with a single hob. A solitary cupboard containing: one cup, one plate, one bowl, one pan. In the only drawer, one knife, one fork, one teaspoon, one dessert spoon, one ladle, one breadknife. One sink in the corner.

The floor was soggy. Sucking at the detectives’ feet like a bog. Not surprising. A man had bled to death there.

The body lay on its front, over the implement that had bled the life from it. The solitary kitchen knife, missing from the drawer. Now sunk deep into the dead man’s belly, handle and all.

He was a big man. As if he had tried to compensate for the emptiness of his life by expanding his own physicality to fill it. He looked like he had dedicated himself to the task. When there is nothing much in your life, there is always eating.

“Who is he?” asked Detective Inspector Stafford.

Detective Sergeant Ringer consulted his notes. “Douglas Quimp.”

“What do we know about him?”

“Bit of a loner, by all accounts.”

“You don’t say.”

“The way I see it, guv, is he killed himself. Fell on his kitchen knife. Given his weight, there would be no going back. That explains why the knife was driven so deep into him. Either it was suicide or a freak accident. But the only possible explanation is he did it himself. The door was locked from the inside, with the key still in the lock. There’s no other way out, what with those bars on the only window, not to mention the drop.”

“I do love a good locked room mystery,” said Stafford. “You don’t get them that often.”

“Unless you’re Jonathan Creek,” said DS Ringer.

“Who he?”

“A fictional character.”

“Yeah, well, this is real life.” Stafford’s tone was belligerent. As if he saw existence as a struggle between the real and the fictional, and he was on the side of the real. “So who found him?”

“The landlord. Alerted by the smell and the flies. And the blood dripping through the ceiling of the flat below. Oh, and the fact that Quimp’s rent was due.”

Stafford examined the door. It was still intact but the frame around the lock was smashed away in big splinters. “Rotten.”

“The key was in the lock. The door had to be broken down for the landlord to get in,” explained Ringer.

“Do we have a time of death?”

“A precise time of death has yet to be confirmed. But judging by the flies, and the smell, he’s been dead for several days.”

“Have we spoken to the neighbours? Does anyone remember anything? Any arguments? Sounds of a struggle?”

“No. Nothing.”

“They must have heard that falling over,” observed Stafford, nodding down towards the body.

“Well, if they did, no one’s saying anything.”

“A conspiracy?” wondered Stafford.

“Perhaps. Or perhaps everyone was out when he topped himself.”

“Alone in death, as in life. Anything else I need to know?”

“Nothing really. We found this in one of his pockets.” Ringer held up a key in an evidence bag. “It fits the lock.”

“Let me see if I’ve got this right. One bed, one chair, one cupboard, one hob, one plate, one pan, one knife, one fork, one spoon…”

“What’s your point?”

“Two keys.”

“Well, he had a spare, naturally. And no one else to give it to.”

Stafford scowled, unconvinced. “Let me have a look at that key.”

It was a standard brass bitted key for a lever lock, with the shaft of the key extended slightly beyond the bit.

“Now let me see the one that was left in the door.”

At first sight, the two keys were identical.

But Stafford was never content with first sight. “What’s that?” He pointed to a rough blob of silver on the tip of the second key, the one found in the door.

Ringer shrugged.

Stafford turned his attention to the door. He noticed a thin trail of liquid streaked from the lock. He pressed his nose close to the lock and sniffed. A silicone whiff just discernible over the stronger stench. “Who broke it down?”

“A local copper. The landlord called the police. That’s how we know for sure the key was still on the inside and not placed there after the door was smashed open.”

“Let’s talk to this landlord.”

The landlord lived in the basement flat, as far away from Quimp as he could arrange it. He also turned out to be as thin as Quimp was fat. Stafford took one look at him and knew he was the killer. It was that old enmity between the lean and the corpulent. Besides, Quimp owed him money.

More than that there was the smell of rosin on him. Another old-fashioned smell. It took Stafford back to his father’s shed. His father had been a great meddler and fixer. Never happier than when he was putting together some broken piece of junk.

“Do you have a pair of pliers?” was Stafford’s first question.

“Oh, yes,” said the thin landlord, proudly. “I have all manner of tools in my workshop.”

“A soldering iron?”

The landlord’s pride deserted him. His expression now was wary. “Why do you ask?”

“You look like the kind of man who would have a soldering iron. To be honest, you look like a soldering iron.”

“What’s this about?”

“It’s about the dead man upstairs. It’s about the thin rod you soldered to the end of a key so that you could insert it into his lock with the rod protruding on the other side. Thin man, thin rod… looking at you, it’s obvious. You could then leave his room, close the door, turn the key with a pair of pliers gripping the rod, which, perhaps, you had flattened slightly at the end. Of course, you made sure that the lock was well-lubricated with WD-40. You turned the rod carefully, till you had it locked, then snapped the rod off with a sharp twist. That’s what this is about.”

“Wrong! You’re wrong!” cried the thin landlord.

Stafford’s smile was strangely triumphant. “How am I wrong?”

“It wasn’t WD-40. It was Permatex.”

“I knew that,” said Stafford. “WD-40 is petroleum-based and Permatex is silicone-based. And I smelt silicone in the lock. Plus, you should never put WD-40 in a lock and I was sure a handyman like you would know that. I deliberately got it wrong so you’d correct me. Thin people are generally more uptight than fat people, and therefore less likely to let a mistake go uncorrected. I knew you wouldn’t be able to stop yourself. Was that why you killed him? Correcting the mistake of letting him the room in the first place?”

The thin landlord was led away.

“Nice one, boss,” said Ringer. “Though I don’t think you can say that stuff about thin people these days. Reckon it’s size-ist.”

“I used to be thin,” said Stafford, as if that explained everything. And maybe it did.