What to watch: Marvel’s Iron Fist and ‘Underground’ war secrets among top TV bets

As he investigates, River finds himself talking to the spirit of his old partner and realizing what he didn’t see before. River, who witnessed it, isn’t sure if it was murder, suicide or a hit and run. He’s haunted by visions of the recent death of his colleague, “Stevie” Stevenson (Nicola Walker), who was hit by a car. Catch up onRiver: (Netflix) If you like to settle down with a good British mystery, this six-part series from 2015 created and written by Abi Morgan (“The Hour,” “The Iron Lady”) is just the thing. “River” has all the conventions of a standard mystery, while at the same time being unconventional. It stars the terrific Stellan Skarsgård as John River, a London Police detective.
Monday on Smithsonian) A documentary about the discovery in Northern France of a vast underground city beneath a farm field where World War I soldiers, on both sides of the conflict, took refuge a century ago.Cries from Syria: (10 p.m. Wednesday on OWN) This drama is set within a black megachurch in Memphis and focuses on the Greenleaf family, which runs the church. Keith David plays the family patriarch and bishop of the church. Monday on HBO) Helen Mirren narrates the documentary from Oscar-nominated director Evgeny Afineevsky about the humanitarian crisis in Syria.Greenleaf: (10 p.m. This weekAmericans Underground — Secret City of WWI: (8 p.m.
All 13 episodes stream today.The Originals: (8 p.m. Marvel’s Iron Fist: (Available Friday on Netflix) Fourth Netflix Marvel series stars Finn Jones stars as Danny Rand, a martial-arts expert with the ability to call upon the power of the Iron Fist. Friday on CW) Fourth season of the “Vampire Diaries” spinoff.Striking Out: (Available Friday on Acorn) USA premiere of the hit Irish legal drama.

Guests (and puppet voices) include Carol Burnett, Alec Baldwin, Ellie Kemper, Josh Groban, and David Hyde Pierce. Namour: (Available Wednesday on Netflix) Drama acquired by Ava DuVernay’s production company follows the experience of an Egyptian immigrant living in Los Angeles.Snatch: (Available Thursday on Crackle) Series is an adaptation of the 2001 Guy Ritchie movie and stars Rupert Grint.Deidra & Laney Rob a Train: (Available Friday on Netflix) Movie dramedy is about a smart high school senior, Deidra, who has been helping to raise her younger sister and brother but not has to bail out her mother, too.Julie’s Greenroom: (Available Friday on Netflix) Julie Andrews hosts a new Jim Henson Company-produced children’s series.