The series follows the work of a missing persons unit, and stars Reece Shearsmith as protagonist Sean Stone, a detective sergeant, and Alex Kingston, as advisor Ruth Hattersley.

[2] DS Sean Stone (Reece Shearsmith) is intense and socially awkward, a misfit who is happier dealing with data rather than people.

His lack of people skills and forthright honesty make him some powerful enemies in the force, and he finds himself exiled to missing persons.

Sean's new caseload is overwhelming - up to 300,000 people go missing in the UK each year - but his brilliant mind turns out to be perfectly adapted to his new role.

DCI Pryor (Noel Clarke) has ambitions and a clear plan for rising up the ranks, but all this is jeopardised when DS Stone becomes his responsibility.