1.

The Appeal, by Janice Hallett

The year’s most original mystery is told in the form of e-mails and text messages primarily from a group of English villagers feverishly raising funds for a child’s cancer treatment. Hallett lets just enough doubt emerge from the burble of voices to make you wonder which ones to trust. A skeptic’s delight.

2.

The Ink Black Heart, by Robert Galbraith

Like its titular fictional cartoon, J. K. Rowling’s latest Cormoran Strike novel is so immersive it can swallow you whole. The evils of online trolling are all too familiar to Rowling, and she leans into its shocking cruelty by showing how the master manipulator who murdered the cartoon’s co-creator confounds the efforts of Strike and his partner, Robin Ellacott, to drag them out from behind the screen.