Doctor Who, a new spin-off titled Torchwood became the first to be commissioned as a full television series. In contrast to its parent show, Torchwood was initially conceived by creator Russell T Davies as an "adult" programme to be broadcast post-watershed. It is set in modern-day Cardiff and revolves around a team investigating alien activities and crime. The series features John Barrowman, playing former Ninth Doctor companion Jack Harkness, police officer Gwen Cooper, computer expert Toshiko Sato, medic Owen Harper and "support man", Ianto Jones. The first episode aired 22 October 2006 and received a record BBC Three (and all British cable television record for a locally produced non-sporting event) high rating of 2.4 million viewers. The first series (Oct '06-Jan '07) comprised 13 episodes broadcast on BBC Three, and was followed by a second 13-part series (Jan '08-Apr '08) broadcast on BBC Two. A third series was written as a 5-part miniseries titled Torchwood: Children of Earth, airing on five consecutive nights from 6–10 July 2009 on BBC One. A fourth series was similarly structured as a single story told as a 10-part miniseries, titled Torchwood: Miracle Day; unlike previous series, Miracle Day was a co-production between the BBC and the US cable television network Starz. The fourth series premiered on 8 July 2011 on Starz in the U.S. and on July 14, 2011 on BBC One in the United Kingdom. The 2006 and 2007 series were companioned with a CBBC show entitled Totally Doctor Who. Series 1 was presented by CBBC and Smile presenter Barney Harwood and Blue Peter presenter Liz Barker. For the show's second series Barker was replaced by SMart presenter Kirsten O'Brien. During the second series, an animated serial, The Infinite Quest, was featured. David Tennant and Freema Agyeman reprised their roles from the live-action television series while Anthony Head, a guest star during the 2006 season, returned in a different role. A second major spin-off of Doctor Who was The Sarah Jane Adventures, created for a younger audience on CBBC, starring Elisabeth Sladen as the Doctor's former companion Sarah Jane Smith. It began with a 60-minute pilot episode co-written by Davies and Gareth Roberts, premiering on BBC One and the CBBC Channel on New Year's Day 2007; the full series started on 24 September 2007, consisting of two-part serials with half-hour individual episodes. Five series were produced altogether, the first four series consisting of