Gwen Cooper (Eve Myles) is a beat cop in Wales who witnesses something very strange when a slain body is found. She sees members of the mysterious Torchwood bring him back to life. Then, the next day she comes across a strange alien called a "Weevil", which kills a hospital employee by biting out his neck. Gwen is ultimately hired by Captain Jack Harriman (John Barrowman) when she shows some gumption about finding out what Torchwood is. Torchwood is a secret organization that protects the world against aliens and alien technology. It just so happens that this part of Wales is on a rift, through which this all comes. Other members of the team include Owen, a doctor, Tosh, a computer genius, and Ianto, who seems like the Butler. As for Jack himself-- he's a bisexual immortal time traveler from the 51st Century. His character was first introduced during David Tennant's stint on DOCTOR WHO.
Gwen end up taking the place of a member who tried to killer her in that first episode.
She also has the worst first day ever, when they investigate a fallen piece of space junk and release an ethereal alien that lives off of orgasms, killing men in the process. It has inhabited a young teenaged girl and Gwen is willing to sacrifice herself in her place because she feels so responsible for the situation to begin with. Then, in another episode, they come across a device that allows to see--and feel-- emotional scenes from the past. Owen witnesses a murder that happened forty years earlier. But it also shows the future and Gwen sees something very unpleasant...
Then, we learn Ianto, one of the members of the group, has been keeping a secret. He had saved his girlfriend, who was half-converted into a cyber-man (a Doctor Who reference) and has to deal with that. It does not end well. And then there are the Faeries. They were all once children, though they have transformed into something else entirely. Now they have a "Chosen One", a child who is to join them in their realm and become one of them. It's something Captain Jack can't stop because to prevent it from happening will have dire repercussions for the entire planet. In one of the season's most unsettling episodes, they go out to the countryside to investigate disappearances by campers. It appears as if it could be because of an alien, like the "Weevils", but the culprits are all too human. They are cannibals. Owen and Gwen, who had kissed in a previous episode, sleep together. Talk about an unlikely pair. However, Owen has a brief affair with a woman pilot who has time-travelled from the 1950's through The Rift and is heart-broken when she decides to leave him and fly back through it.
This first season ends with Jack stopping the gigantic, life-sucking demon that comes out of The Rift by letting it overload with his life-force and it seemingly kills him. But, of course, he comes back to life. And just as this happens we hear the familiar sound of Doctor Who's Tardis, Jack's face lights up, and then the rest of the group find that he's gone (this ties in with the third season of Doctor Who, I believe).
I'm a fan of DOCTOR WHO but I like TORCHWOOD better because it's able to take more risks in terms of characters and storytelling.