Review of the Complete Story:
This four-part Tom Baker story was Elisabeth Sladen's final appearance as Sarah Jane and the final moments provide a fitting, poignant closure for her character. Story-wise, it's business as usual with the Doctor involved with a rapidly-evolving alien life form that's just arrived on earth. The opening shots see the Tardis arrive in a quarry, so it's nice to see a quarry playing just that, a quarry, for once instead of standing in for an alien planet. Following a spectacular filmed explosion, the action shifts to a nuclear power plant where much of the ensuing action takes place.
The idea of a life form thriving on radiation is a good one, and there's fun to be had from the severed/crawling hand prop (and a nod to CARRY ON SCREAMING!) when the hand regrows both a digit and a body! Some stiff-upper-lipped British officials populate the cast, and are quite fabulous, although once the action shifts to an extraterrestrial planet in the last episode it does get noticeably weaker. Judith Paris was a strange, Bowie-esque alien presence, but Stephen Thorne's scenery chewing becomes quickly tiresome.
The cheesy-looking alien "rock men" brought back fond memories of HERCULES AGAINST THE MOON MEN, a reminder of how much fun this show was when all they had going were a low budget and plenty of enthusiasm. Not one of the best stories out there, but perfectly serviceable nonetheless.