The Tomb of the Cybermen

The Tomb of the Cybermen was the first serial of season 5 of Doctor Who. It introduced the first Cyber-Controller and the Cybermats.

It is the earliest Second Doctor serial to survive in its entirety and, from its recovery in the early 1990s until the recovery of The Enemy of the World in 2013, it was the only complete serial extant from season 5.

Synopsis
The TARDIS arrives on the planet Telos, where an Eartharchaeological expedition led by Professor Parry is trying to uncover the lost tombs of the Cybermen. With a lot of help from the Doctor, the archaeologists enter the tombs. There, one of the party, Klieg, reveals himself and his business partner, Kaftan, to be planning to revive the Cybermen.

He wants to use their strength, allied with the intelligence of his own Brotherhood of Logicians, to create an invincible force for conquest. It transpires, however, that the tomb is actually a giant trap designed to lure humans suitable for conversion into Cybermen — a fate that almost befalls Kaftan's assistant Toberman.

After fending off an attack by Cybermats — small but dangerous cybernetic creatures — the Doctor destroys the Controller, defeats the revived Cybermen and reseals the tombs.