In my opinion, and the opinion of many other fans, this story is one of the best of all time. The Caves of Androzani gives the 5th Doctor the very finest send off possible and Peter Davison not only is brilliant in this story he is given superb material to demonstrate the full potential of his Doctor. Robert Holmes contributed so much of the best work on Doctor Who both as writer of many great stories and script editor overseeing the greatest era of the show in Tom Baker's first few seasons. Here he has written another immaculate script and excellent plot. The intelligence and quality of the dialogue is as good as it gets and the dark, gritty story full of action but also deeper themes makes for an adventure that is thoroughly impressive and absorbing.
The Doctor and Peri get caught up in a 3 way battle of intrigue, violence and greed where different factions seek to exploit the mining of a hugely valuable elixir of youth. Meanwhile both Peri and The Doctor suffer poisoning which leaves them facing death unless an antidote can be found.
As well as Peter Davison on top form this boasts an entire cast providing top notch performances. Christopher Gable as Sharaz Jek creates one of the finest villains in the history of Who. He is cunning, clever, has a wonderful way with words and has great menace. In addition, the character has depth in how he shows the trauma he has suffered and how it drives him to insanity. John Normington is also perfect as ruthless leader Morgus and other characters are all spot on. I am not a fan of Nicola Bryant as Peri but this story and the material provided gloss over any weakness in that role.
The only element which is not as well realised on screen as it could be is the Magma Beast which is not very good but does not detract from overall quality. The rest of the effects, set and production values are top Doctor Who standard.
Simply phenomenal. 10/10