Review of all 4 episodes:
This marks the first appearance of a Sontaran in Doctor Who. A race of alien warrior that would become an icon in the show right up to the present day. The design and realisation of the Sontaran in this debut is absolutely superb. Kevin Lindsay puts in a great performance as Sontaran warrior Linx and the costume, make-up and original design are of top quality.
The story is a 'pseudo-historical' where much of it is set in England in the time of Richard I (1189-1199 AD) with Linx having been stranded there by his damaged spacecraft but able to drag scientists from 1970s England back to force them to help him fix his craft. The Doctor follows back to the 1100s in the TARDIS along with stowaway journalist Sarah Jane Smith who becomes The Doctor's long serving companion. Her debut is great, with Elizabeth Sladen's wonderful performance giving a taste of how she would become the most enduring and most loved companion the Doctor ever has. She manages to be strong and independent but charming and feminine at the same time. That is thanks to the exceptional acting and characterisation by Lis Sladen and the writing of the part by Robert Holmes. She is incredible right from the start!
There is also another first, the first mention of the name of the Timelords planet, Gallifrey. A very notable addition to the lore.
There is a lot of great fun, action and great scripting by the legendary Robert Holmes along the way with only a few less successful scenes which are simply due to the limitations of the 1970s production values. It is funny at times, has good levels of menace at other times and the whole concept is fantastic.
Jon Pertwee is on absolutely top form and there are some excellent guest performances from June Brown (of future Eastenders fame) as Eleanor, Alan Rowe as Lord Edward, Donald Pelmear as Professor Rubeish and Jeremy Bulloch (who later was the original Boba Fett in two Star Wars films) as Hal.
This is a brilliantly entertaining story with the greatest possible new companion and a great new alien menace. A joy of an adventure and a real classic!
My rating for all 4 episodes: 10/10.