“The Strain” is a mostly successful attempt at serialized horror, adapted from the vampire novel of the same name by Guillermo del Toro and Chuck Hogan.  It’s a smart, fun, dark genre-buster combining a conspiracy thriller, an action adventure, a plague thriller and good old fashioned gross-out monster mayhem — there are even dashes of historical fiction via flashback.

It’s an ambitious story even for the original novel, covering vampirism as a viral epidemic that sweeps New York City.  The putative heroes are two CDC investigators — though viewer loyalties will shift from these stock characters to the cooler and more interesting supporting characters — the tragic old curio shop owner; the quirky, gigantic exterminator; the local petty criminal; and the penitent computer hacker.  The little boy is such a one-note character that he might as well be a prop.

The exterminator, Vasily Fet, is played beautifully by sci-fi fan favorite Kevin Durand. (I can’t help but wonder if the character’s last name is a “Star Wars” reference.)  He’s a good actor, and his size and voice make him damn interesting as either a hero or a villain.  (See “Lost.”)  David Bradley, the curio shop owner around whom much of the plot revolves, does a great job, especially considering how cheesy the dialogue given to him sounds.

But by far and away, actor Richard Sammel steals the show.  He is simply a fantastic bad guy — creepy, unsettling, frightening, hateful, insinuating and mysterious.  This show has a great villain, and I liked rooting against Sammel’s creep far better that I liked rooting against the somewhat cartoonish “Master.”

For much of the time, the combination of the above story elements works out well.  “The Strain” can be surprisingly creepy for a network show.  The creepy-crawlies look great, even if they are reminiscent of “the reapers” of “Blade II” (2002), also directed by del Toro.  (Wouldn’t it be great if there were a shared universe?)  I’ve always thought that one of the scariest aspects of the vampire mythos was that loved ones can become enemies — the series wisely capitalizes on this more than once.  And the entire conspiracy plotline actually is pretty unsettling, as it’s scripted convincingly and with some thought behind it.

Regrettably, all of these good things can’t sustain the scares and tension over the course of a full season of television. Once they are faced and defeated more than once, the vampires do lose a bit of their punch.  The flashbacks to Europe (trying to keep this spoiler-free) grow tiresome and predictable, no matter how cool and original the idea started off.  And compounding this is a great lack of tension supplied by the actors and screenwriters.  Everyone is way too relaxed.  It is probably the end of the world, via vampire apocalypse, and these chipper folks often seem like they’re kids meeting to work on an afterschool project.  This isn’t helped much by a final action set piece that is directed so awkwardly it’s embarrassing.

Still, “The Strain” really is worth a look, at least if only to see if it’s your cup of tea.  I actually do recommend it.

A  little trivia — several episodes were directed by none other than RoboCop himself, Peter Weller.