Shona Sandison might be about to get her biggest scoop yet if she can make it to the end of the investigation alive.

In a darkening, post-COVID world, fearless investigative reporter Shona Sandison is seeking meaning and her next big story. A secret contact inside the government has promised her something huge, but she has no idea of the danger she is in. Meanwhile, her old friend Hector Stricken has taken on a position in communications for a new state agency, where he stumbles across a sinister, top-secret project codenamed 'Grendel'. And on the Scottish coast, an ageing spy chief, living in seclusion, grieves his murdered son and contemplates revenge.

Connecting them all is an insidious conspiracy within the UK's most powerful institutions, a rot so deep that the only way to cure it may be to cut it out or burn the whole thing down.