Day One (Torchwood)

02 – "Day One"
Torchwood episode
The Gas takes over Carys's body.
Cast
Starring
Others
Production
Directed byBrian Kelly
Written byChris Chibnall
Script editorBrian Minchin
Produced byRichard Stokes
Chris Chibnall (co-producer)
Executive producer(s)Russell T Davies
Julie Gardner
Music byMurray Gold
Ben Foster
Production code1.2
SeriesSeries 1
Running time48 mins
First broadcast22 October 2006 (2006-10-22)
Chronology
← Preceded by
"Everything Changes"
Followed by →
"Ghost Machine"
List of episodes

"Day One" is the second episode of the first series of the British science fiction television series Torchwood. Directed by Brian Kelly, the episode was first broadcast on the digital channel BBC Three on 22 October 2006 with the series pilot, "Everything Changes", and later repeated on terrestrial channel BBC Two on 25 October. It was the first work in the Doctor Who universe to be written by future Doctor Who showrunner Chris Chibnall.

The episode centres on Gwen Cooper (Eve Myles) working her first case with the alien hunters Torchwood in Cardiff, when she lets loose a purple alien gas[broken anchor] that survives on the energy of orgasms. Over the course of the episode, the team hunt for Carys before the gas kills her.

Originally entitled "New Girl", the episode was written to interpret Gwen's "first day in hell". On the sex gas, series creator Russell T Davies stated "when we're launching a new adult science fiction drama, it's kind of inevitable you're going to do the sex monster". The episode was filmed during a three- to four-week period in May 2006, with much of it filmed before the first episode in the same production block. "Day One" was originally seen by 2.3 million viewers, making it one of the highest-rated BBC Three broadcasts of all time, but was met with generally mixed reviews.