What’s On: A dark adaptation of ‘Agatha Christie’s The Witness for the Prosecution,’ and Team ‘Timeless’ goes rogue

Agatha Christie’s The Witness for the Prosecution (Acorn TV): There’s nothing the least bit cozy about this bleak, bold new adaptation of a Christie chestnut by Sarah Phelps, whose thrilling And Then There Were None last year was the best and certainly the darkest I’ve ever seen. Set in a post-WWI London cloaked in gloomy fog and wracked by loss and sorrow, the superbly acted Witness stars Toby Jones (recently seen as a Sherlock villain) as a rheumatic, melancholy lawyer whose young war-vet client, Leonard Vole (Billy Howle), is charged with murdering his wealthy lover (Kim Cattrall, in a sharp cameo). Vole’s fate hinges on the testimony of his inscrutable wife, the Austrian showgirl Romaine (Andrea Riseborough), whose motivations throughout the high courtroom drama are unclear until the diabolical end. If you end up believing no one in this grim fable is innocent, the Prosecution will have successfully rested its case.

Timeless (10/9c, NBC): You had to know this would happen, that Wyatt (Matt Lanter) would find a way to get Rufus (Malcolm Barrett) to take the time-tripping Lifeboat on a very personal rogue mission: to wipe out the bloodline of his wife’s killer from being born and thus change his own history. (Because that worked out so well for Lucy?) Speaking of Lucy (Abigail Spencer), she has the unenviable task of covering them, because it’s kind of hard to keep the absence of even a rickety time machine a secret.

Dick Van Dyke and the Other Woman (11/10c, getTV): In yet another nostalgic look back at a highlight of Mary Tyler Moore’s TV career, this 1969 musical-variety special, which reunited Moore with the co-star of her breakthrough TV hit The Dick Van Dyke Show, is often credited with giving her career (stalled on the big screen) the boost it needed for The Mary Tyler Moore Show to premiere one year later. This special is followed by an episode of the 1960 cult drama Johnny Staccato (midnight/11c), in which she plays an endangered beauty-pageant contestant who turns to the title private eye (John Cassavates) for help.

Inside Monday TV: Making way for midseason premieres next week, including the highly anticipated 24: Legacy, Fox presents winter finales of Gotham (8/7c), with the resurrected Jerome (Cameron Monaghan) on the loose, and Lucifer (9/8c), which sends the title demon back to hell. Gotham returns April 24, and Lucifer May 1. … National Geographic Channel’s The Story of God With Morgan Freeman concludes its second season by exploring “Proof of God” (9/8c), and whether it’s still possible to divine the presence of the divine in the modern world. … The HBO documentary Becoming Warren Buffett (10/9c) gets up close and personal with the unassuming billionaire investor, the temperamental opposite of the current inhabitant of the White House.