I will say this for "Legends," the new TNT drama (it debuts tonight at 9) starring Sean Bean: it does not attempt to hide Bean's native accent behind some bland non-regional American dialect, at least not in his main identity as FBI agent Martin Odom. Because Odom is a master of assuming undercover identities (the "legends" of the title), Bean gets to try on various semi-convincing accents the rest of the time, but at least "Legends" doesn't waste time trying to convince us that Ned Stark doesn't sound like Ned Stark when he's not playacting. The explanation for how a man with this accent ended up working for the FBI is utterly ridiculous, but it's also one line of dialogue that never has to be dealt with again, and it's an approach that I wish many more shows would take when hiring actors from the UK, Australia or New Zealand.

For a show that is about a man who is never who he appears to be, "Legends" winds up being exactly what it appears to be in every possible second: a generic crime procedural tricked up with a convoluted mystery meant to add intrigue to the various Undercover Assignments of the Week. It is unapologetic about this, and about how it casts every regular and guest actor so ruthlessly to type that they may as well be going by the names they've used in previous roles exactly like these. So Tina Majorino from "Veronica Mars" again plays a computer genius, Zeljko Ivanek turns up in the first episode as a charismatic villain, Steve Harris is the stern authority figure, and, as Martin's handler, Ali Larter even has to put on one of her old "Heroes" stripper outfits midway through the very first episode.

The only one not cast to type in this way is Bean himself. Bean is not known as a chameleon of a performer. He's known as the sturdy guy who comes in, gives your project enormous gravitas, and then dies so that you can get to the actual story(*). He has a very distinct look that's hard to disguise, though he and the show's costume and makeup people do what they can with props, wardrobe and accent choices. He never disappears into any of his cover identities, but you can imagine a world in which he might be plausible as a recruit in a white supremacist militia, or as a successful arms merchant. And the pilot does have one strong scene where he explains the backstory of his latest legend to Larter and the team, as we see him slip on the character, layer by layer. It's a basic actor's exercise, filmed in tight close-up, but an effective way of demonstrating how Odom does what he does.

(*) TNT is even trying to turn the audience's knowledge of Bean's career arc to its advantages, attaching the hasthag #DontKillSeanBean to all its "Legends" advertising. It may not be enough: at Comic-Con, I passed two guys staring up at the enormous "Legends" ad plastered across the side of my hotel, with the hashtag in lettering almost as big as the show's title. "Eh, that could be fun," said one of them. "At least until they kill Sean Bean in episode 8," said the other.

Undercover shows are hard to do as procedurals, though, because the most interesting aspect of them is the notion of the operative being stuck in this false identity for an extended period, like Vinnie on "Wiseguy" or Donnie Brasco. "Legends" opens with Martin wrapping up a six-month assignment, but after that, the structure seems to be for him to assume and discard identities in rapid order — sometimes inventing wholly new ones, sometimes dusting off ones he's used previously that he can reactivate at a moment's notice — in a way that removes much of the intrigue and emotional danger of the premise.

The show attempts to compensate for that by introducing a mystery about Martin's past that is, like the rest of the show, so factory-made that at one point, he's even told, "Trust no one!," as if he were a character on "The X-Files," which was one of "Legends" producer Howard Gordon's earliest jobs. "Legends" wants you to take it very seriously, but throughout the two episodes I've seen, it plays like a parody of the kind of show it wants to be.

Alan Sepinwall may be reached at sepinwall@hitfix.com