This is a story about murder in a literal family tree. The Witch Elm (Viking) of the title looms over Ivy House, the Hennessys' ancestral home. When they gather for tea one spring Saturday, a skull is found hidden in the hollow of its centuries-old trunk.

These are not good times for the Hennessys. Toby, the golden boy, has suffered a series of personal and professional setbacks. First, he nearly loses his PR job at a gallery over an art-fraud scandal, but his boss decides to keep him on. He celebrates his lucky break by going out drinking with his chums. When Toby later stumbles back to his apartment, he surprises a pair of robbers, who beat him so badly he's left with severe head trauma. Too unsettled by the attack to stay in his flat, Toby moves to Ivy House hoping to recover in a soothing place and spend time with his Uncle Hugo, who's dying of brain cancer. For a short while, peace reigns. 

Then there's the gruesome discovery in the backyard, and the novel shifts from poignant family drama to breathless thriller. Who among the relatives is capable of murder? Until now, Toby has remembered his childhood as bucolic, if not idyllic. However, his cousins have a very different recollection of summers at Ivy House. As the detectives uncover clues, Toby searches his own unreliable memory and is unable to make the case for his innocence or anyone else's. 

Fans of Tana French's Dublin Murder Squad series know her to be a high priestess of tense, twisty plots, but in The Witch Elm she travels a new path, exploring the complexities of identity. While the mystery's resolution is astonishing, it is not the emotional center of this tale of loyalty and its shadow twin, resentment. Hugo's illness presages a changing of the guard, forcing the cousins to re-examine everything. 

Death can coalesce a family or tear it apart. It turns out that's especially true when that death happens to be a murder.