The extended finale will last for 60 minutes and will conclude at 9pm. Death in Heaven, penned by head writer Steven Moffat, will air on the same day on BBC America at 9/8C.
With Cybermen on the streets of London, old friends unite against old enemies and the Doctor takes to the air in a startling new role.
Can the mighty UNIT contain Missy? As the Doctor faces his greatest challenge, sacrifices must be made before the day is won.[Source: BBC]