In my book you cannot get better classic Doctor Who than stories involving the Doctor and Sarah Jane Smith. Story 80 Terror of the Zygons is one such DVD. It is here that the Doctor affects a Tam o'Shanter and solves the mystery behind the Loch Ness Monster and why a series of oil rigs in the North Sea are being destroyed.
Terror of the Zygons is a variation on a classic Doctor Who plot of a race of aliens stranded on earth, eons ago in this case, who suddenly decide it is time to take over the earth. In this case in the fourth and final episode of this story.
The Zygons may be just rubber-suited actors but they do have one special talent that is to my knowledge unseen until then in the series.
The story itself is quite enjoyable though not remarkable. The way the Doctor stops the Zygon invasion is very lame. Then again, the Zygons never come across as particularly menacing.
The special effects, especially that of the rig being destroyed are laughable even by 1975 standards. The Loch Ness monster makes inflatable pool toys appear realistic in comparison. Fortunately, the story is quite enjoyable and Tom Baker gives at times a most affectedly weird interpretation of the Doctor.
By the way, the innkeeper is played by Angus Lennie who also played Ives in The Great Escape.
Special features are plentiful on this two DVD Doctor Who release. These include a commentary track with the producer, the writer, nd a couple of others; An extended first episode (there was a scene taken out of the original); Two segments of Doctor Who Stories, one with Tom Baker, the other with Elisabeth Sladen; The UNIT Family part three; a feature on Douglas Camfield, one of the Doctor's directors; a visit to an oil rig, and an interview clip with Baker at the time of the filming of this episode