The story falls into the "howdunit" category, that particularly unique subset of mystery stories that MacDonald enjoyed writing so much. The reader can usually spot the gears turning in these tales, where it becomes obvious that the author has come up with a unique way of committing a crime and then builds his story around it, but in the hands of someone like MacDonald it doesn't matter, as the expert writing and characterization take over and completely overshadow any seams that may be visible in the storytelling. With "Black Cat in the Snow," he uses setting and -- especially -- character, to make an obvious plot into a really engaging work of fiction.
The setting is standard MacDonald, here a remote town "in the wildest part of the Adirondacks" in upstate New York, a place obviously modeled after Speculator, NY and his summer home on Lake Piseco. Here he calls it Pattenberg and it is winter, after all the summer campers have left and only the nine hundred permanent residents remain. Told in the first person by an unnamed town doctor, the story opens in his office on a typical day of seeing patients. He is interrupted by a call from State Trooper Jerry Jackson, informing him that a local resident has been shot and that he will be coming by shortly to pick the doctor up to head out to the remote farm where the shooting took place. When the doctor tells his office manager that she needs to inform the waiting patients to either leave or plan on a long wait, she asks why. When he tells her that Martin Wadaslaw has been shot, he detects "a little gleam of satisfaction in [her] eyes." Wadaslaw, it seems, was not a nice guy.
"I am as charitable toward my fellow man as anybody, but I'd never been able to find a trace of good in Martin Wadaslaw. He was born mean and he lived mean. He had been a lumberjack, and when a chain broke about twelve years ago, he lost a leg and got a pension from the lumber company. At that time he had a bunch of halfgrown kids and a wornout wife. Before his accident he drank heavy enough to keep his family in short rations, and so the kids old enough to work were doing what they could. Good kids. Bright and hardy and energetic. The accident should have killed Martin -- would have killed a normal man -- but he was too mean to die. There's some say that the men who had to work with him had something to do with that chain breaking, but maybe that's just gossip. After Martin began to spend all his time home, his wife lasted about two years before she died, and the kids began to scatter."
Now all that were left living on the Wadaslaw place were Martin's unmarried daughter Rose, his son Stanley and Stanley's wife and two kids. Stanley, it seems, it the polar opposite of his father, a good-natured, charitable family man who runs a lodge up on a nearby lake in the summer, but who returns home with his family every winter to live with his disagreeable father.
When the doctor and the police arrive, they find that Martin is "dead and gone," shot by his own son Stanley, only Stanley claims it was an accident. He had been in the kitchen when he saw a large flock of crows out in the side lot. He grabbed a Winchester .22 bolt action and headed out to scare them away, but by the time he got out there the birds were out of range so he turned to go back inside. Just then the family's black cat ran from the barn to the nearby shed, treading over a well-worn path it seemed used to using.
"'For no reason at all,' Stanley said, 'I decided to fire close behind her. You know. Startle her a little. I was aiming toward the house of course, but into the snow. I'm a good shot. The cat jumped in the air and ran twice as fast. The old man gave a funny kind of grunt and sat down in the snow and rolled over on his side. I didn't know what happened. I thought maybe he had a heart attack. After we got him in the kitchen, then I saw the hole in his shirt and a little blood. So I phoned right away.'"
According to Stanley, his bullet ricocheted off of the snow, hit the side of the barn, and came back toward the house, hitting his father as he watched from the porch. Trooper Jackson is skeptical and takes the gun outside and fires several shots right where Stanley claims to have aimed. Sure enough, the slugs hit the barn and ricochet exactly as Stanley had claimed they did. The doctor takes the body back into town and does an autopsy, revealing nothing that would contradict Stanley's story. There is no investigation and Martin is buried beside his wife and "two kids who hadn't lived long enough to grow up."
But it is a long winter and the good doctor has plenty of time on his hands. "I guess one of the penalties of a country practice is that you get too much time to think, and you get too curious about people and the way their minds work." So he begins to do a bit of his own off-hours investigating...
"Black Cat in the Snow" was one of only six short stories MacDonald had published in 1958, a far cry from the early years when he produced multiple scores of works for the pulps and slicks of the day. He did, however, have four novels published that year -- one of which was the milestone work The Executioners -- as well as magazine versions of three of those books printed in Cosmopolitan, Redbook and Ladies Home Journal. Although his focus had switched to the longer form, "Black Cat in the Snow" is good evidence that he could still knock off a little gem of a tale whenever he wanted to.
The story has been anthologized at least twice that I know of. In 1987 Bill Pronzini and Martin H. Greenberg included it in their mystery collection titled Suspicious Characters, and in 1997 it was included in the anthology titled Purr-fect Crimes, a collection of cat-centered mystery stories edited by Carol-Lynn Rossel Waugh, Martin H. Greenberg and Isaac Asimov. Both are out of print but are easy to find used, for very reasonable prices.