Review of all 4 parts:
This brilliant story sees the return of Brigadier Lethbridge-Stewart, one of the most important friends in the Doctor's whole history and he returns in a full, very involved role not just a cameo. The story involves a complex plot with time travel/time loops which in modern day Whoniverse would be referred to as 'Timey Wimey'. It is brilliant.
The TARDIS arrives aboard an alien spaceship in Earth year 1983 and The Doctor travels via a Transmat to Earth in that year but his companions following him in the TARDIS end up in the same place but in 1977. This brings about great. clever and interesting time related ideas with them meeting the Brigadier in both time periods and trying to reunite without the Brigadier meeting himself. There is only one flaw in the whole story which is that the 1977 period seems to clash with our understanding of the Brigadier's work with UNIT. It would have been better if they had used the Royal Wedding of 1981 rather than the Silver Jubilee of 1977 and maybe had a near future 1986 instead of 1983. Anyway it is insignificant compared to all the strengths of this adventure.
As well as the time travel to two Earth years with the Brigadier in both and the complexities that introduces we also get two other strong plot aspects. First is the Black Guardian arc which begins with the mysterious villain influencing a young man Turlough to try to kill the Doctor. This is given further depth by the mystery surrounding Turlough himself. It is extremely intriguing and well done. Turlough is a great character and the Black Guardian is a suitably menacing figure.
The other plot aspect is the alien travellers aboard the spaceship lead by Mawdryn. It brings further intriguing, exciting and sometimes macabre elements which further strengthen an already superb serial. Mawdryn himself is excellent and the events of all 3 plot threads move along fantastically well and come together cleverly.
The added effects in a later re-release add wonderful sheen to the already high production standards but most importantly the storyline, dialogue and acting is of the highest quality. There are intelligent ideas, thrilling scenes, absorbing drama, strong characters and great camaraderie. The return of the Brigadier is a master-stroke with Nicholas Courtney as wonderful as ever.
In addition to the Brigadier and new companion Turlough we get a top level performance from Peter Davison as The Doctor. Tegan and Nyssa are OK and are used well.
Overall this is a 10/10 classic across all 4 episodes.
