SERIES PREMIERE: Sean Bean stars in this new TNT series, playing a deep undercover operative who sometimes gets lost in the roles he’s playing. In other words, it owes a lot to the Nineties CBS series Wiseguy, and even a little to the Seventies series Baretta, in which Robert Blake adopted weekly personas to bring down that episode’s villain. Legends breaks little new ground in this regard, and is watchable only because Bean is a charismatic leading man, and, past that, only if you find perverse pleasure in watching how quickly the series resorts to tired genre conventions. How long does it take before Ali Larter from Heroes, as Bean’s tough-as-nails superior and handler at the agency, joins him on an undercover assignment by posing as a lap-dancing stripper? Three commercial breaks, tops. Not that I’m complaining, really. It’s just that I’m not surprised – and in the best moments from the other shows where executive producer Howard Gordon’s name is attached, such as 24 and Homeland, surprise is one of the most potent ingredients. Not here. At least not at first.