Lost is back once again, wrapping up its fourth season with a block of six hours (over five nights). And the first new installment looks to be the most violent in ages. Plus, PBS has two new documentaries that look to the future: one of which is sunny and optimistic, featuring stars from one of your favorite NPR shows. And the other of which is gloomy and may make you want to slit your wrists. But never fear: your future also includes new episodes of Smallville, Battlestar Galactica and Spectacular Spider-Man! Full listings (with minor spoilers and clips) below.

Tonight

It's sort of a wasteland tonight. I've scoured the TV listings, to no avail. Sci Fi is having its usual Monday night Star Trek: Enterprise marathon. The Oxygen network is showing Catwoman twice in a row for some ungodly reason — and yes, I know Catwoman isn't science fiction, but it is an object lesson in the absolute worst way to do a superhero movie, plus the worst use of CGI ever. (Halle Berry's butt is CGI. Why???) Ummm... the History Channel has a new Cities of the Underworld, about Stalin's secret city under Moscow, which could be a springboard for all sorts of alternate history.

Note to self: Next week, on Monday and Tuesday, Letterman has Gwyneth Paltrow and Robert Downie Jr,. promoting Iron Man two nights in a row.

Tuesday

Nova has a new episode about the "Car Of The Future." This may actually be better than it sounds, for a few reasons. For one thing, it features the hosts of NPR's Car Talk hitting the road to look at possible future cars. They'll talk to alternative-technology gurus and test-drive cutting edge cars. Check your local PBS listings for time.

And then on the History Channel at 9, there's a new episode of The Universe, all about scientists studying the nature of gravity.

And at 8 PM, AMC has back-to-back War Games and King Kong (the 1976 version featuring Jeff Bridges and Jessica Lange.) The two movies sort of blend together into an examination of our primal fears: out-of-control technology and bestiality.

Wednesday

PBS has the very apocalyptic sounding National Geographic's Strange Days On Planet Earth, a two-hour special about how everything is fucked. It's the first time this periodic series has appeared since April 2005. The latest episode is about how stocks of commercially important fish are 90 percent depleted, and how the death of the oceans may affect other life on Earth in ways that we can't see immediately. It doesn't feature the guys from Car Talk, but it still could be worth watching.

TMC has a David Cronenberg double feature at 8 PM and 9:45: Existenz followed by Shivers, two very different takes on the "body horror" motif, one involving video games that jack into your spine and the other involving weird parasites that make you into a rampaging sex fiend.

The History Channel has four UFO Hunters in a row, but I think they're all reruns. Starting at 12:30 (noon-ish), AMC is showing the War Games-King Kong combo again.

Thursday

There's a new Smallville on The CW at 8 PM. Here's the official description:

Clark (Tom Welling) desperately searches for Kara (Laura Vandervoort) and Brainiac (guest star James Marsters, as Brainiac is the only one who can reverse Lana's (Kristin Kreuk) condition. Clark asks Chloe (Allison Mack) to check any large power surges in the area, so she breaks into several government computers, setting off alarms. Jimmy (Aaron Ashmore) is caught between the Department of Security - who threatens him with jail time unless he helps them arrest Chloe - and Lex (Michael Rosenbaum), who offers to help clear Chloe if Jimmy agrees to be in his debt.

And there's that new Lost episode. Other-ton comes under attack, and Locke and Ben have to work together to defend themselves. Here's a preview clip:

Also, FX has the first big Fantastic Four movie (not the Corman version) at 8 and 10 PM.

Friday

Once again, Sci Fi has a strong line-up. At 8 PM, there are two half-hour episodes of the Doctor Who spin-off, the Sarah Jane Adventures. They include the final episode of "Revenge Of The Slitheen," which is where you first see that the kid-friendly Sarah Jane can actually be a teeny bit subversive after all, and also create a cast of engaging characters who actually seem to care about each other and work well as a team. There's also the first episode of "Eye Of The Gorgon," the one about the kinky nuns.

Then at 9 PM, Sci Fi has the real Doctor Who fourth season opener, as opposed to last week's Christmas special. Donna, the loudmouth who appeared in the 2006 Christmas special, is back as this season's full-time companion. But this time she's taking more of an initiative, investigating a crooked alien corporation that's doing something sort of hard to explain with diet pills. You can read our recap of the episode here.

And at 10 PM, there's another new Battlestar Galactica, the post-apocalyptic space-opera show that's gotten its groove back after a bit of a slump last year. In "Escape Velocity," Chief Tyrol deals with what happened this past Friday, and Gaius Baltar starts getting more vociferous about promoting his one-true-god beliefs among the humans — leading to a debate about religious freedom. Here's the trailer:

Saturday

Saturday is all about the animated shows again. Spectacular Spider-Man has two episodes at 9:30 AM on The CW — one of which is new. It's the big prom, and Mary Jane is threatening to overturn the social order at Peter Parker's high school. But even more seriously, the Green Goblin wants to unseat Tombstone as the Big Man of crime in the Big Apple. Is Peter willing to screw up his date in order to stop the Goblin?

Meanwhile, Ben 10: Alien Force moves to its new time on Saturdays at 10 AM on the Cartoon Network. "Gwen discovers that Grandpa Max's badge is able to signal other Plumbers. By using it, they meet up with a familiar face, a pyronite! " And then there's a re-run of Transformers: Animated.

Sunday

FX is showing Sam Raimi's original Spider-Man at 8 PM.