The Next Doctor quite like "The Next Doctor"." The book also contained two pictures from a scene cut from the end of the previous episode, intended to segue into the special echoing the previous two series. This scene was included on the series boxset. Following the success of last year's Christmas special, "Voyage of the Damned", which guest starred pop star Kylie Minogue as one-off companion Astrid Peth, Russell T Davies had initially felt tempted to copy this format with another high-profile guest star, but decided against it after jokingly offering up "Cheryl Cole on board the "Hindenburg"" as an example. Regarding an
Companion (Doctor Who) in the Series Four finale "The Stolen Earth" / "Journey's End" (2008), which features a record eight past, present and future companions: Donna is joined by a returning Rose, Martha, Jack, Sarah Jane, and Mickey, while past companion K9 and future companion Wilfred Mott make appearances. This tendency, plus the increase in "one-off" companions like Astrid Peth and Jackson Lake, has further obscured the matter of who is and is not a companion. The Doctor's companions have assumed a variety of roles—involuntary passengers, assistants (particularly Liz Shaw), friends, and fellow adventurers; and, of course, he regularly gains new companions and