The greatest geek candy here is the addition of Buffy cast member James Marsters as recurring rogue Capt. John Hart. The most touching moments early on belong to Helen Raynor's "To the Last Man," about the plight of a World War I soldier whom Torchwood has kept in suspended animation and revived once a year for eight decades, and Catherine Tregenna's "Meat," in which ordinary guy Rhys (Kai Owen) gets his first real glimpse of the professional life of his fiancee the Torchwood agent.

The most disturbing event is the unusual death of Dr. Owen Harper (Gorman), "unusual" in that circumstances leave him mobile and active and aware even as his undead condition deprives him of every other attribute of life. This requires no small adjustment on his part, and an entire episode, and one of the season's best episodes, Joseph Lidster's "A Day in the Death," concerns just about how one goes about regaining the will to live when life itself is not part of the equation.

Harper's situation, which includes an inability to heal and the implication that the rest of his existence will be an exercise in being whittled down to the bone by the inevitable accumulation of injuries, is a horrific one that isn't quite allowed to play out to its inevitable end before a bigger catastrophe intervenes in the final episode, Asley Ways's "Exit Wounds."

Slapstick to Lovecraftian horror

The darkness abates long enough for Phil Ford's "Something Borrowed," in which an alien parasite saddles Gwen (Myles) with an instantaneous late-term pregnancy on the morning of her wedding; wackiness and much irritation on the part of the in-laws ensue.

But that's just a palate cleanser before the true Lovecraftian terror of what may be the single most despairing moment of the entire series so far, Chris Chibnall's "Adrift." In that black and literally hopeless story, Gwen finds out something that Capt. Jack Harkness (Barrowman) would have preferred her not to know: that the lost teenager whose disappearance she's been investigating is now being held as an inmate in a Torchwood medical facility, where time anomalies and horrific experiences among the stars have reduced him to a scarred and disfigured 50-year-old. Gwen hopes to reunite him with his mother anyway, but she has failed to consider that he might harbor scars far deeper, and far more horrifying, than the physical. In "Adrift," the universe is not just vast and unknowable, but downright malignant, and woe awaits any luckless human being who steps in the wrong place while on his way home to Mom.

Extras on the DVD set include deleted scenes, most of them not very interesting, and outtakes, which are actually funny for once. A documentary on the many deaths of the immortal Capt. Jack Harkness, with scenes gleaned from both this series and Doctor Who, includes an admission on the part of John Barrowman's stunt double, Curtis Rivers, that he had been hoping for regular work and thought the on-screen death in the first episode he worked meant that he was unemployed again. He was, you can guess, very happy to find out that Capt. Jack can bounce back from any injury, a condition that offers the character's stunt double wonderful job security.