He'll play Jack Reinhold, based on the role originated by David Bradley, as an older, unmarried man who runs the kayak rental on the beach near the small town of Gracepoint and becomes a suspect in the murder of a little boy.
Gracepoint brings Tennant (Doctor Who) back to play the American counterpart to his Detective Inspector Alec Hardy, a hardened city cop recently relocated to the small town in the hope of escaping a scandal in his past. He immediately gets on the bad side of Detective Ellie Miller (Olivia Coleman, handing off to Breaking Bad's Anna Gunn), who hoped to get the top police job but loses it to Hardy.
The two team up to investigate the murder of Danny Latimer, 11, and their search leads them to Reinhold, as well as Susan Wright (Silver Linings Playbook's Jacki Weaver, taking over from Pauline Quirke), and a slew of other townspeople including Danny's father, the local reverend, and others.
Gracepoint, which begins filming in Vancouver next month, is set for broadcast in the 2014-15 season.
A second season of Broadchurch is scheduled to begin production in 2014. The original series aired on ITV in the U.K. and on BBC America in the U.S.