Pop star Kylie Minogue is to star alongside David Tennant in this year's Doctor Who Christmas special.
TV bosses say Kylie's got a "major lead role" in the hour-long episode - Voyage of the Damned - which starts filming later this month in Cardiff, Wales.
The story follows on from series three, when viewers saw the famous Titanic ship crash through the Tardis walls.
Writer Russell T Davies said: "This will be the most ambitious and best Christmas episode yet."
The current series of Doctor Who ended on Saturday, when viewers saw the Doctor's companion Martha leave life in the Tardis to look after her family.
She will be back, but in the meantime the Doctor will have to find a new assistant before the fourth series hits our screens in Spring 2008.