called "Red Dwarf". Kochanski is supposedly dead and Holly is offline due to water damage caused by Lister leaving a tap running. Actress Sophie Winkleman played a character called Katerina, a resurrected hologram of a Red Dwarf science officer intent on replacing Rimmer. To achieve a more cinematic atmosphere, Back to Earth was not filmed in front of a studio audience. Some previous Red Dwarf episodes had been shot in that way ("Bodyswap" and all of the seventh series), but Back to Earth represented the first time that a laughter track was not added before broadcast. It was also the first episode of Red Dwarf to be filmed in high definition. The specials were televised over three nights, starting on Friday 10 April 2009. The broadcasts received record ratings for Dave; the first of the three episodes represented the UK's highest-ever viewing figures for a commissioned programme on a digital network. Back to Earth was released on DVD on 15 June 2009, and on Blu-ray on 31 August 2009. Back to Earth was subsequently described on the series' official website as "for all intents and purposes, the 'ninth series' of Red Dwarf". This placement was confirmed when Series X was commissioned and branded as the tenth series, although Back to Earth continues not to be referred to as "Series IX" on home media or digital releases. Red Dwarf X On 10 April 2011, Dave announced that it had commissioned a six-episode series X to be broadcast on Dave in late 2012. Filming dates for the new series Red Dwarf X were announced on 11 November 2011, along with confirmation that the series would be shot at Shepperton Studios in front of an audience. Principal filming began on 16 December 2011 and ended on 27 January 2012, and the cast and crew subsequently returned for six days filming pick-ups. Discounting guest stars, only the core cast of Charles, Barrie, Llewellyn and John-Jules returned for Series X, with Annett and Lovett absent, though the scripts include references to Kochanski and Holly. On 20 July 2012, a 55-second trailer for series X was released on Facebook, followed by a new "teaser" every Friday. The new series debuted on Thursday 4 October 2012. Red Dwarf XI and XII Following series X, which attracted high viewing figures, Dave, Doug Naylor and the cast showed strong interest in making another series. During the Dimension Jump fan