As the emotional roller-coaster that is Battlestar Galactica launches its fourth and eventually final season, I find myself marveling again at its psychological depth, its relentless intensity, and its provocative mix of political, spiritual and military intrigue.

This series has TV legend written all over it. Equally concerned with inner and outer space, Battlestar is that rare show worthy of being mentioned alongside The X Files, Buffy the Vampire Slayer and Lost for its ability to use dark fantasy to explore the nature of humanity so deeply and honestly it often hurts to watch.

And yet, it's also too enjoyable not to. The combat is thrilling, the twists always surprising — in the opener, I must have shouted, "Oh, no, he (or she) didn't!" a half-dozen times.

But oh, yes, they do go there, repeatedly, to the most unexpected and disturbing places. In Battlestar, the ultimate battleground is for the soul.

Last season ended with the shocking discovery that four key players aboard Galactica are somehow secret Cylons (the robotic race seemingly intent on wiping out humans) and have been all along — though, like us, they've been in the dark until now. Does this change who they really are?

And what of warrior supremo Starbuck (Katee Sackhoff), presumed dead but newly and mysteriously back from Earth in a spotless ship? Even father figure Adama (Edward James Olmos) doubts her, wondering: "Should I believe my heart or my eyes?"

Good question. Everyone's an enigma in this universe, including the corrupt outcast Baltar (James Callis), who goes into hiding amid a cultish harem of fangirl acolytes convinced he's a new messiah.

Simply put, the journey of Battlestar Galactica is one long, exhilarating headtrip. Come aboard if you dare.

Battlestar Galactica, Season Premiere: Friday, April 4, 10 pm/ET, Sci Fi channel (also online via video.tvguide.com)

Wire in the Blood

As if we didn't have enough crime dramas, here comes BBC America importing one to Texas. The good news: It's among their best.

Based on Val McDermid's chilling novels, Wire in the Blood opens its fifth season by sending hero Dr. Tony Hill to hot, dusty Texas (filmed in Austin). Hill (Robson Green), a forensic psychologist, is flown in by prosecutors after an Iraq War vet confesses to the brutal murder of his wife and children. The doctor's and soldier's paths previously crossed in England, and Hill doubts that post-traumatic stress is behind the crimes.

But there's plenty of stress in the investigation, as Hill's sheepish charm and bizarre mental flashes don't exactly endear him to the locals. "Place like this, you can see the need for alien abduction," Hill gripes.

Green (the original Touching Evil) is an electrifying star who deserves to be better known in the U.S. I hope this isn't his last visit to these shores.

Wire in the Blood, Season Premiere, Sunday, April 6, 8 pm/ET, BBC America