The Sanatorium

High in the Swiss Alps, an isolated luxury hotel — once a tuberculosis sanatorium, now sleekly renovated into all glass and steel — keeps the unsettling architecture of its grim past. Detective Elin Warner, on leave and shaken by a recent case, arrives for her estranged brother's engagement celebration, uneasy from the moment she steps inside.

When her brother's fiancée vanishes without a trace and a body soon follows, a violent snowstorm severs the hotel from the outside world, trapping guests and staff with no way down the mountain and no help coming. Elin is the only person present with any investigative training, and she must push past her own trauma and self-doubt to find a killer who is very much still among them — even as the building's history begins to feel less like decoration and more like a warning.

The first novel in Sarah Pearse's Detective Elin Warner series, The Sanatorium is a chilly, claustrophobic locked-setting thriller that leans hard into atmosphere: remote, snowbound, and steeped in dread. It became a runaway bestseller and a Reese's Book Club pick.