A MURDER MYSTERY CONUNDRUM

INSPECTOR PARNACKI was enjoying his Sunday morning newspaper when the call came. An hour later, he was standing outside the door of one Harold Rivera, a mathematician who worked for a large firm in the city. The detective on the scene opened the door to let him in.

“Good to have you here, Inspector,” said the man. “My name’s Burrell. I’ve spoken to the victim’s cleaner and made a few enquiries, but it’s not getting me anywhere.”

“What can you tell me about the victim, Detective Burrell?”

“Harold Rivera, 48, lived alone. No spouse, children, or near family. Mathematician for Longmuir & Sons, accountants. He seems to have devoted his spare time to chess. He had several regular chess partners, and very little social life otherwise. The body was found in the living room. He was killed by a blow to the head, twelve to twenty-four hours ago.”

“I should have a look,” said Parnacki.

“Of course.” Burrell led him down the hall and into a modest living room.

There was a small couch and coffee table, but the room was dominated by a table holding a large, fine china chessboard. Two smaller tables, each with their own chessboard, were off to the side. Games were in progress on all three tables, but white appeared to be in a particularly strong position on the large table, with the middle of the board dominated by three adjacent mid-level pieces, the two white bishops separated by a white knight. The floor in front of the board was heavily stained with blood, as was the plain wooden chair lying on it.

“He lived alone?” asked Parnacki.

“Yes. A cleaner comes for two hours every day, generally mornings. She’s the one who found him. Apparently, the small tables were always mid-game, and she was under extremely strict instruction never to touch them. He used them to keep track of play-by-mail games, he had told her. The big one was for face-to-face contests.”

“I see,” Parnacki said. “Do we have any idea of why anyone would want to kill a chess fanatic?”

“From what the cleaner said, he could be very rude at times. Accidentally, that is. No malice, just poor social skills. Way I see it, one of his chess pals finally snapped and killed him.”

“Well, it might explain the game.”

Burrell nodded. “We found a note on the coffee table. Three names. The cleaner confirmed it was the victim’s handwriting, and said he often made notes of who to expect that day. To prepare himself, she said. Alphabetical order, sadly.”

“Of course,” said Parnacki. “How else would a logician order names?”

“Two are regular chess partners,” Burrell said. “The third, it turns out he’s a work colleague. Thomas Creech is a loner, like Rivera. Thirty-eight. A lawyer’s assistant. I spoke to him – he said he was going to come over in the afternoon, but he had a cold, so he cried off. Matthew Norton is a bad writer, forty-two. He’s the other chess guy. He said he was going to visit in the evening, but he got distracted reading about bears, forgot the time and decided it was too late to visit. The colleague is Brendan Cotton. They work in the same section. He said he did come over, after lunch, to discuss a troublesome client account. It was something he did occasionally. He remembers noticing that the big chessboard was empty.”

“Excellent work, Detective,” Parnacki said. “You’ve solved the murder.”

“I have?” Burrell sounded highly doubtful. “I thought I’d barely begun digging.”

Parnacki nodded. “I can tell you who the murderer is right now.”

Who killed Rivera, and how does Parnacki know?