The final episode comes down to two battles, The Doctor v The Master, and the Colonists v The IMC crew.
The Master is about to destroy Jo, when the primitives arrive and imprison them both. Jo is released. We learn why The Master wanted to gain access to the primitive's city. Naturally the Master has a concealed weapon, allowing him and the Doctor to roam free in search of the Doomsday weapon. IMC force the Colonists to fire up the engines and take off. Caldwell and Jo break in to the City in order to rescue The Doctor. The Guardian intercedes and destroys the city, the Doctor, Master Jo and Caldwell escape as it explodes, taking the Doomsday weapon with them.
Great scene between The Master and The Doctor, discussing the Primitives history and the Doomsday weapon.
The fight in the clay between a guard and Winton is really effective, well realised and possibly the high point of the episode.
The Primitives have been fairly badly designed, they look like giant runner beans with spears, whereas the Alien priests look particularly unconvincing.
Why did the Guardian suddenly hit the self destruct button, it truly made absolutely no sense.
Nicholas Pennell's character Winton improved a lot as the story went on, he put in some good performances in the latter episodes.
A good story idea which was very averagely realised. Part 6 has at least been more interesting then the last few, it's been desperately overlong, Dicks and Letts should have had the sense to cut it down to 4 parts, they continually commissioned 6 parters, they should have learned a lot sooner that the 4 part stories worked better.