Set in the 1950s, this six-part British TV series follows Agatha Christie's popular husband-and-wife sleuths Tommy (David Walliams) and Tuppence Beresford (Jessica Raine) on a pair of perplexing mysteries. On a Paris train, the duo searches for a missing woman who was in possession of a secret recording that may expose a Soviet assassin, in "The Secret Adversary." And, "N or M?" finds Tommy and Tuppence tasked with discovering who's behind the theft of a prototype for a nuclear bomb. 5 1/2 hrs. total on two discs. Widescreen (Enhanced); Soundtrack: English Dolby Digital 5.1; Subtitles: English (SDH); behind-the-scenes footage; featurettes; photo gallery.