defying gravity ron livingston abcThis week, Ron Livingston gets lost in space as Defying Gravity returns to Sunday night, and a Stargate Atlantis alum visits Warehouse 13 (no it's not Rodney McKay!). Read on for this week's sci-fi TV picks.

Defying Gravity, "Threshold" - ABC's new space drama is no Virtuality – there's little darkness or hard sci-fi elements, and the vibe is anything but existential – but it's not exactly Grey's Anatomy in space either. The first hour of last night's premiere was a well-constructed look at a team of young astronauts facing the biggest journey of their lives. Still, there wasn't much for sci-fi fans to get excited about except for Ron Livingston's (Office Space) likeable performance as a down-and-out spaceman (his hammy voiceover works surprisingly well) and some decent-looking outer space FX shots.

The series' main focus is on the various romantic entanglements of the crew of the spaceship Antares. Unfortunately, the characters seem more concerned with their sexual relationships than exploring the cosmos. Some clumsy storytelling and a few questionable casting choices (is it too late to re-cast Ellen Pompeo clone Laura Harris as the female lead?) might sink this one before it gets a chance to soar. So why am I still watching? The creepy mystery plot has me hooked.

The show's sci-fi elements come front-and-center this week as the Antares' crew suffers cellular and psychological transformations courtesy of the mysterious force manipulating their mission. (Sunday, 10 p.m. ET on ABC.)

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Warehouse 13, "Elements" – Pete and Myka do some digging in an ancient Indian burial ground. Stargate Atlantis vet Joe Flanigan guest stars as Jeff Weaver, a charming and wealthy man who catches Myka's attention. (Tuesday, 9 p.m. ET, Syfy.)



Eureka, "If You Build It ..." - More fun and charming feel-good sci-fi as Carter tries to discover why and how a group of teens are reconstructing the town. (Friday, 9 p.m. ET on Syfy.)



Being Human, "Episode 3" - The new show about a vampire, a ghost and a werewolf living together delivered some fine freaky drama last week. This week, the boys take Annie out for a drink and try to discover what was left unfinished before she left her body. (Saturday, 9 p.m. ET on BBC America.)