Sometimes, a murder mystery is centered on that network of relationships. For example, Martin Edwards explores this theme frequently. In The Coffin Trail, the first of his Lake District mysteries, he introduces Oxford history don Daniel Kind, and DCI Hannah Scarlett. There seems on the surface to be no reason the two should know one another; yet, they have a connection. Kind’s father, Ben Kind, was Scarlett’s senior partner before his death. Years before, he and Scarlett had investigated the murder of Gabrielle Anders. It was always assumed that a local young man, Barrie Gilpin, had killed her, but Kind and Scarlett weren’t convinced. When Scarlett’s named to lead a local Cold Case Review team, she decides to re-open the case. Daniel Kind also has a connection with Gilpin; he knew Gilpin when they were young, and he doesn’t think Gilpin killed Anders, either. This network of relationships not only plays an important role in the mystery, but it also adds much to the story. The same is true in Edwards’ The Cipher Garden, the second pairing of Kind and Scarlett. In that novel, the two of them investigate the murder of Warren Howe, a landscaper whose wife was the prime suspect in his killing. She had an alibi, though, so the police couldn’t pursue the case. Years later, Scarlett and her team re-open the case when they receive an anonymous tip about it, and Kind gets interested when the solution to his own puzzle – the mysterious shape of the garden at the cottage he’s taken – leads him to the landscaping firm that employed Howe. In this novel, too, the pattern of relationships and the connections among the characters is directly related to Howe’s murder.
Agatha Christie also based several of her mysteries around networks of relationships. For example, in A Holiday For Murder (AKA Murder for Christmas and Hercule Poirot’s Christmas), Hercule Poirot investigates the murder of Simeon Lee, whose unpleasant personality has alienated everyone in his family. When he invites the members of his family to spend Christmas with him at the family home, he claims it’s because he wants to renew the ties with his children and their spouses. No-one believes him, but everyone accepts his invitation, for different reasons. On Christmas Eve, Lee is brutally murdered, and Poirot, who’s staying at the home of a friend nearby, is asked to investigate the case. What he finds is that Lee’s murderer had a connection with Lee that no-one suspected. Here is an excellent review of this novel by Dorte at DJs Krimiblog.
There’s also a fascinating connection in Christie’s The Mirror Crack’d (AKA The Mirror Crack’d From Side to Side), in which Miss Marple investigates the poisoning murder of Heather Badcock. The town of St. Mary Mead gears up for the arrival of Marina Rudd, a famous actress who’s bought Gossington Hall, formerly owned by Col. and Mrs. Bantry (and, by the way, the setting for The Body in the Library). Marina Rudd is Heather Badcock’s favorite actress, so Heather eagerly attends the grand opening of Gossington Hall to see her idol. Moments after they meet, Heather is stricken by an attack that turns out to be poison. At first, everyone thinks that Marina Rudd was the intended victim. She’s famous, and has alienated her share of people. Besides, she gave her own drink to Heather, so it’s assumed that the poisoned drink was meant for Marina. Miss Marple soon learns otherwise, though. As it turns out, there’s a connection between Heather Badcock and Marina Rudd that no-one suspected.
Perhaps Christie’s most famous study of networks of connections is Murder on the Orient Express (AKA Murder in the Calais Coach), in which Hercule Poirot investigates the stabbing death of a wealthy American businessman who’s traveling on the world-famous Orient Express train. The only suspects in the murder are the other people traveling on the same coach. However, they’re all apparently strangers to each other and to the dead man, and there seems to be no motive for any of them to have killed him. Then, Poirot finds a clue that gives him the connection – and the motive for the murder.
In Rita Mae Brown's Rest In Pieces, there's apparantly no connection between a scruffy, eccentric stranger who shows up in tiny Crozet, Virginia, and the people who live there. But when that stranger turns up dead, postmistress Mary Minor "Harry" Haristeen believes that there are connections. What she finds out is that the lives of the stranger, her new next-door-neighbor, and one of the older families in town have been intertwined.
There’s also apparently no connection between a group of American tourists visiting Oxford, and Dr. Theodore Kemp, the curator of the Ashmolean museum in Colin Dexter’s The Jewel That Was Ours. None of the tourists knows Kemp. And yet, first, a famous jewel that one of the tourists was going to donate to the museum is stolen. Then, Kemp is murdered. When Inspector Morse and Sergeant Lewis are put on the case, they find an intriguing network of connections among the tourists and between them and Kemp. That connection led directly to Kemp’s death.
Dexter’s The Daughters of Cain also has as a main focus the unexpected connections and relationships among people. Morse and Lewis are in search of the murderer of former Oxford don Felix McClure. As a part of the investigation, Morse meets Ellie Smith, a prostitute who counted McClure among her “regulars.” In a fascinating twist on the “small world” adage, it turns out that Ellie’s got another connection to the case that becomes apparent when McClure’s former scout, Ted Brooks, goes missing.
Sue Henry’s Degrees of Separation also deals directly with the unexpected connections between people. In that novel, the twelfth of her Jessie Arnold Alaska series, Arnold has recuperated from a knee injury and wants to return to sled dog mushing. She’s practicing one day when her sled hits an unexpected bump in the trail that turns out to be the frozen body of Donny Thompson, the son of a local mechanic. Jessie’s live-in boyfriend, Alaska state trooper Alex Jensen, begins to investigate the case and, despite her better judgment, Jessie gets involved, too. She tries to avoid getting involved, but as it turns out, this death and another murder that occurs later in the novel both hit close to home for Jessie.
Even when an unexpected connection isn’t the cause of a murder, it can still be an interesting plot point. For example, in Agatha Christie’s Hickory Dickory Death (AKA Hickory Dickory Dock), Hercule Poirot investigates the murder of Celia Austin, a young resident of a hostel for students. He finds that her death is directly related to a number of hidden secrets that other hostel residents are keeping. One of the fascinating – and sometimes unexpected – revelations in the story is the connections among the residents. It turns out that several of them work in the same hospital. Three of them have business connections that we don’t know about at first, and there turns out to be a family relationship between two of the characters that also plays a role in the novel.
There’s another example in Christie’s The Clocks, in which Hercule Poirot solves the murder of a mysterious stranger whose body has ended up in the home of Millicent Pebmarsh, a blind schoolteacher. The body’s discovered by Sheila Webb, a typist who was sent there to do some typing for Miss Pebmarsh. When she discovers the body, Sheila runs out of Miss Pebmarsh’s home, screaming – straight into the arms of Colin Lamb, a member of the Secret Service who’s in the neighborhood for quite a different reason. Lamb’s father was a friend of Poirot’s so Lamb takes the case of the dead stranger to Poirot to challenge him to solve the murder. At the end of the novel, we find that Sheila Webb has a surprising connection with the case.
As usual, I’ve only sampled from a few novels in which the networks and connections among people play important roles in crime fiction. I’m sure that you can think of many more. Do you enjoy these networks – the degrees of separation? Or do you think they’re too contrived?