BEFORE SHE KNEW HIM

Peter Swanson (Faber, £12.99)

A desperate woman, in mortal danger, who is the only person to know the truth about a murder but can’t make anyone believe her. It sounds like a tired old premise, but Peter Swanson gives it an unexpected freshness in this invigorating psychological thriller.

It begins in West Dartford, a small town in Massachusetts. Married couple Hen (short for Henrietta) and Lloyd have recently moved in and are invited round for dinner by their new next-door neighbours, Matthew and Mira. Hen, a children’s book illustrator, is a little reluctant to go. At college, she was admitted to a psychiatric hospital after attacking another student whom she claimed was evil, and although her bipolarity is kept stable with medication she’s still shy about meeting new people.

After dinner, in Matthew’s study, Hen spots a fencing trophy and almost faints. A while back, during one of her manic phases, she had read everything she could about Dustin Miller, a student who was murdered on the street she used to live on. She’s convinced that the trophy is Dustin’s, and that Matthew killed him, taking the trophy from his apartment as a memento.

The thing is, against all the odds, she’s actually right. Her new neighbour, Matthew, did murder her old neighbour, Dustin. And Matthew has noticed Hen’s shocked reaction. Suddenly afraid, he curses his arrogance for leaving the incriminating item out on display and disposes of it, along with all the other “souvenirs” of men he’s murdered.

The question left hanging in the air between Hen and Matthew is where they go from here. She knows, and he knows she knows, but without any evidence what can she do? Hen, of course, has previous form in making accusations against innocent people.

So what starts off as a cat-and-mouse game evolves into a weird and uneasy intimacy. Hen, whose artworks have always betrayed her morbid streak, gets to commune with a man who knows true darkness, while Matthew, for the first time in his life, finds a confidante with whom he can discuss his crimes. He wants to explain himself, get Hen to understand how his sadistic, misogynistic father set him on the path to killing men who hurt women. But the dynamic Hen and Matthew have established is not stable, and it won’t take much to nudge them into very dangerous territory.

There’s not a trace of padding, and Swanson’s pacing is exemplary. He knows how to ration his twists and where in the narrative to place them, devoting just the right amount of time to exploring the ramifications of each new development before spinning the story off in an ominous new direction. And if a lot of what he’s doing is juggling around well-used tropes from suspense fiction, the way he does it is so smart and exciting that you’re just happy to get swept along by the compelling storyline and not stop to examine the nuts and bolts. Brian De Palma, or Hitchcock, were he still alive, would kill for the film rights.

ALASTAIR MABBOTT