Series 4 (Doctor Who)

The 2009 Specials will be broadcast between the end of Series 4 and the beginning of Series 5. Five specials will be broadcast at various points in 2008-2009. Of the five specials, one has been scheduled for Christmas 2008, one for Easter 2009, and one for Christmas 2009, leaving the other two unscheduled. These five specials will be overseen by Russell T Davies and Julie Gardner, but traditional line producer, Phil Collinson, will not be returning for them. All will reportedly star David Tennant.

David Tennant announced that after the 2009 specials he would leave Doctor Who. Rumoured actors to replace Tennant are David Morissey (appearing as another Doctor in The Next Doctor), James Nesbitt and Russell Tovey (who appeared as Midshipman Frame in Voyage of the Damned).

Christmas 2008
The 2008 Christmas Special is entitled, The Next Doctor. The Cybus Cybermen are known to be returning. Also, actors Dervla Kirwan and David Morrissey are involved, as is a probable setting of Victorian England.

Attendees of the 2008 San Diego Comic Convention were amongst the first members of the public to have this setting confirmed. In a trailer shown at the convention, Christmas Eve 1851 was established at the narrative date. Anecdotal accounts claim the trailer also showed what appeared to be a Dalek at one point.

Actor Velile Tshabalala has also been cast in The Next Doctor, playing the role of an East Londoner named Rosita. Rosita begins the special as a companion to the other Doctor (David Morrissey), before she starts helping the Doctor (David Tennant) instead.

For the 2009 Specials, the Doctor will be travelling alone, each episode starring a one-off companion.

Series numbering
Although it was initially thought that the "interval" season of specials might come to be known as Series 5, or Series 4.5, however at present it appears that the BBC will not be assigning a series "number" to the specials, much as the previous Christmas specials and mini-episodes do not technically belong to any particular season. This, however, is contradicted by Russell T Davies himself in his book The Writer's Tale, where he calls The Next Doctor the fourteenth episode of the fourth series (likely due to the fact it was produced during the production of Series 4).

Writers
Russell T Davies is solely writing only the Christmas 2008 special and two others. One of the specials will be co-written by Gareth Roberts, and one will be co-written by Phil Ford. These particular specials will be historic in that they will be the first two episodes of the BBC Wales production of Doctor Who to formally credit a co-writer. With the inclusion of Ford, 2009 will mark the fifth straight year that Doctor Who has included at least one new writer for the show, and make Ford the only writer other than RTD himself to write for Torchwood, The Sarah Jane Adventures and Doctor Who.

Rumours

 * The Sun newspaper in the UK reported Paul McGann is to make an appearance as the Eighth Doctor in one of the specials. However, on 12 September 2008, the BBC refuted this allegation, saying, "There is no truth to the story at all."
 * Actor Patrick Stewart may also appear in the 2009 specials, playing the renegade Time Lord, The Monk. At least one source believes that "the BBC has offered him the role and are willing to wait for Stewart's schedule to clear".  Stewart could therefore appear in either the specials or the 2010 series.
 * One of the specials will retell the Time War.