New series. Three-part adaptation of Agatha Christie's novel, starring Bill Nighy. The former husband of a murdered heiress prepares to remarry 18 months after her adopted son was convicted of killing her, before dying himself in a prison brawl. However, the wedding preparations are disrupted by the arrival of a mysterious scientist who has returned from an expedition to the Arctic - and who claims to be able to prove the supposed murderer is innocent.