Dodo's character being so ineptly conceived that she doesn't even leave on-screen. The War Machines being so boxy. Their terrible power being represented exclusively by crashing slowly through several stacks of crates. This serial lends a lot to The Web of Fear and The Invasion, but is totally outclassed by both of those stories. There's a lot of good stuff here, and 90% of it is Anneke Wills and Mike Craze. Could have been a great story, instead is merely an ordinary one. But it's wonderfully 60s.

Dodo's exit is easily the worst the classic show ever did, which is even more of a shame considering that this story features her at her best in my opinion.

Doctor Who is required

@Icecreamdif Personally I love Doctor Who is required. An endearing memento of a time when they recognised that continuity wasn't that important. The writer thought that was his name and no one thought or bothered to tell him it wasn't.

Dodo's "exit".

I thought Dodo’s exit was pretty fitting. She wandered into the Doctor’s life in The Massacre, and she wandered out of his life in The War Machines.