Despite the discussion between the Time Lords in the very first episode foreshadowing what's coming, this one doesn't even feel like a Master story until he shows up in episode four. But then it makes up for the apparent red herrings of the previous three episodes, and by then the story of the future colonists battling against a mining corporation has you hooked against your will anyway. When the Master does arrive, though, it gets really interesting: disguised as the Adjudicator, he has more clout in this future world than the Doctor does, and for once the Master is in complete (albeit temporary) control. Later, when the two make it to the forbidden city of Uxarieus, it's like watching a preview of the Twelfth Doctor's interactions with the Mistress: the Master wants to use the doomsday weapon created by the planet's indigenous population to take over the universe, and he offers the Doctor an equal share so that the Doctor can bring peace to the universe - through force. Sound familiar? What makes this one better than The Sea Devils, you might ask? Primarily, it makes better use of its length - as much as fans love that sword fight in the other story, they also recognise it as padding.