The Three Doctors (1)
S10, E1: In search of the Doctor, an antimatter creature attacks UNIT and the Doctor is forced to send out an SOS message to his people, the Time Lords, but they have troubles of their own.

S10, E1: In search of the Doctor, an antimatter creature attacks UNIT and the Doctor is forced to send out an SOS message to his people, the Time Lords, but they have troubles of their own.