In 2023, Detective Hasan discovers a dead body in Longharvest Lane, Whitechapel — while in 1941 and 1890, two other detectives find the same corpse.

Hasan follows new leads in the present. As Hillinghead reluctantly closes his case, Whiteman goes to desperate lengths to hide involvement in his own.

Hasan discovers she isn't the only detective investigating a murder on Longharvest Lane. In the past and future alike, relationships start to deepen.