Torchwood is a spinoff off of the Dr. Who science fiction series, being aired by the BBC, CBC, and various other stations around the world. It recently started a new 10 show mini-series.
If you've never seen Dr. Who, it is a science fiction show that has aired at various points over the last 5 decades about a wandering time traveler, his (mostly human) companions and their adventures. The science is humorously bad (but it doesn't take itself seriously), but the thing about Dr. Who that distinguishes it from other science fiction is the Doctor's strong pacifist streak. So faced with palace coups, villanous mad scientists or everly enthusiastic British military outfits, the Doctor often comes up with clever ways of outsmarting them.
Torchwood follows the adventures of Captain Jack Harkness*, a gender and species blind Don Juan, who once traveled with the Doctor. Like the Doctor, Captain Jack is virtually invincible. Unlike the Doctor, he would rather eradicate than negotiate with any alien menace. While the adventures of Dr. Who mainly take place in London, the first several seasons of Torchwood took place in Cardiff. Apparently this itself is a joke, as Cardiff seems to have a reputation of being boring. Why would aliens invade there?
The first 2 season's of Torchwood had little to say for themselves except this episode, and the fact that Captain Jack's universal lust, which is far greater than anything either captain of either Enterprise could acheive, often makes the show sweetly homo-erotic.
The third season, a 5 show mini-series, is brilliant.
This season starts with Captain Jack showing signs of mortality, while everyone else on earth seems to be invincible. There is a new plot twist to bring the action to the US. The sexual undercurrent of the rest of the series is toned down/missing, at least so far. But there are some great scenes, such as a 6 month old wearing earmuffs grinning from ear to ear in her mother's arms as Mum tries to shoot down a helicopter. Good fun. I look forward to the rest of the series.
*If you are interested in Dr. Who, Netflix has many of the episodes streaming. And Captain Jack first appears in the series in what might be the best episode produced in the last 7 years.