Tom Baker effortlessly becomes the Doctor immediately. Its magical.
Even though this is still the Third Doctor's production team of Barry Letts and Terrance Dicks, this story begins a thematic influence that runs throughout the Fourth Doctor's era - particularly the incoming team of Philip Hinchcliffe and Robert Holmes, whereas they borrow from literature and film for inspiration. Here it is Isaac Asimov's I, Robot and the film King Kong...brilliantly combined into a memorable DW adventure.
This is the first DW to be made entirely on video with no film inserts, due largely to the Robot special effects needed for exterior shots.
A big welcome to Ian Marter as Harry Sullivan, a character created in case the new Doctor needed a "man of action," should he be unable to do it all himself (this proved to not be the case once Tom was cast, as he was quite willing and able) - and played by Marter who was considered for Captain Yates way back when.