|Doctor Who-The Hand Of Fear|
Story begins as the TARDIS finds itself in a middle of a mining zone that's being heavily blasted. While avoiding the dynamite Sarah Jane is grabbed by a fossilized hand that,unknown to every else begins to take over her mind. It isn't long before she is hijacked herself in a nuclear power plant and some employees also begin to act strangely in a similar manner. After deducing all these events it's learned that an alien calling itself Eldrad that thrives on radiation is attempting to regenerate it's physical body and return to it's home planet. This effects makes whoever Eldrad is inhabiting impervious to radiation as well. Once the regeneration is complete Sarah Jane and the Doctor find themselves in the presence of a very exotic alien female.
She coaxes them into having them use the TARDIS to help her return to her home planet to correct a problem which destroyed her people. Once this is done,Eldrad is believed to have been smashed to death by a machine she claimed was to regenerate her fully. It's then revealed Eldrad's true form is an esthetically unpleasant criminal who has little to no regard for any other life and was manipulating events all along. Once the doctor and Sarah Jane are able to destroy the tyrant,who in fact was responsible for the destruction of his people out of a petty act of vengeance they return to the TARDIS where the doctor is summoned back to Gallifrey where,in this case he cannot take Sarah Jane. He drops her back on Earth,in her proper time only not exactly in the right place.
This is a very well paced and rather science based concept dealing with mental manipulation and the idea of a life form that feeds off radiation. This results in the scenes where Sarah Jane is possessed by the mind of Eldrad (the famous "ELDRAD MUST LIVE" parts) that include some excellent acting on the part of Sladen. Interestingly as well,in the final scene Sarah fusses at the doctor about wanting to come home. It's not genuine,just her attempt to encourage him to have her do more as an assistant. In the end he has to return her to Earth anyway. So her departure is set up as something of a "be careful what you wish for" type issue. In the end this would not be the last time she would encounter this wandering time lord from Gallifrey.