Unforgotten (2015)

The gold standard, and the one to start with. Each six-episode series reopens one long-buried disappearance or murder in London, then follows several ordinary people whose lives turn out to be tied to it. Chris Lang writes the suspects with as much care as the detectives, so the real subject is what decades of keeping quiet does to a person. Nicola Walker leads the first four series; Sinéad Keenan takes over from series five, and the show holds its quality through the change. Six series have aired, the latest in February 2025, and ITV has commissioned a seventh. Bring tissues for the endings.