Ep 3. Spearhead from Space: Part 3

After being injured in an explosion, the Doctor is rushed to the hospital where he is mistaken for a mentally ill patient. Meanwhile, Liz tries to recover the object that she believes triggers the arrival of the alien meteorites. When she is caught trying to break into General Scobie's office, she is arrested. The rocky, alien meteorites continue to afflict the people of the town, turning them into mindless automatons controlled by an unseen force. Meanwhile, the Nestenes deploy their ultimate weapon to wipe out the Earthlings. In order to stop them, the Doctor must find a way to mount a direct attack on the Nestenes' base. Finally, the Doctor meets a new companion, Brigadier Lethbridge-Stewart, who aids him in stopping the extraterrestrial threat.