Logopolis is the seventh and final serial of the 18th season of the
British science fiction television series Doctor Who, which was first
broadcast in four weekly parts on BBC1 from 28 February to 21 March
1981. It was Tom Baker's last story as the Fourth Doctor and marks the
first appearance of Peter Davison as the Fifth Doctor and Janet
Fielding as new companion Tegan Jovanka.The serial is set on the
planets Earth and Logopolis. In the serial, the Doctor, a time
traveller from outer space, forms a temporary truce with his
arch-enemy the Master (Anthony Ainley) to stop the unravelling of the
universe which the Master had started by accident.Alerted to impending
trouble by the TARDIS's Cloister Bell, the Fourth Doctor decides to
stay out of trouble, and instead repair the TARDIS's broken chameleon
circuit by materialising around a real police box on Earth and
recording its exact dimensions with Adric's help. With those, he can
give the mathematicians of the planet Logopolis the right
block-transfer computations to repair the circuit. The Master learns
of the Doctor's plan, and materialises his TARDIS around the police
box first, causing a recursion loop with the Doctor's. The Doctor
eventually breaks his TARDIS out of the loop, but when they step
outside, he sees a figure in white, the Watcher, telling him to go to
Logopolis immediately. En route, they find they have gained a
passenger, Tegan Jovanka, an airline stewardess who entered the Police
box seeking help for a broken-down car. Logopolis Biography, NetWorth, Height, Age, Weight, Family, Married, Son, Daughter