The Doctor and the Thals escape from the Dalek city and the Doctor is delighted to find Jo is alive. But the Daleks are preparing deadly bacteria to kill all life on the planet.
In the Dalek city, the Doctor breaks out of his prison cell and joins forces with the Thals. With the Daleks in pursuit, he is forced to improvise a daring escape plan.
Desperate to prevent the Daleks from releasing their plague, the Doctor, Jo and the Thals infiltrate their base. But the Daleks detect the intruders!
A force of ten thousand Daleks is coming to life below the surface of Spiridon. The Doctor and the Thals must find a way to defeat the Daleks before they invade the galaxy.
