Critics will say that seven episodes is far too long for a Doctor Who and that it inevitably leads to lots of padding. I believe that the length of 'Inferno' allows for much greater character development, dialogue, plotting and wit than most Doctor Who stories. The story begins with the Doctor and UNIT attending a government drilling project headed by Professor Stahlman (who isn't exactly a villain, just an obsessed scientist). The Doctor suspects that if drilling continues it will lead to disaster and he has found allies in Christopher Benjamin and Derek Newark. The Brigadier, meanwhile, is preoccupied with a brutal murder. The Doctor accidentally slips sideways in time (courtesy of the TARDIS console) to a parellel dimension where his friends are brutal fascists and drilling at the project is at a more advanced stage.