A reluctant Solomon (Colin Baker), along with his former associates Egan (David Troughton) and Saul (John Wadmore), have (they think!) escaped Earth...
Two years have passed since the Nestene creature vanished from UNIT's top secret Warehouse... Suddenly and without warning the Nestene strikes, once...
When Dr Lauren Anderson agrees to Thomas Mordley testing his experimental new drug Cyberon on her brain damaged patients she expects little benefit....