This is a solid adventure, this time putting the Doctor alone with Graham. It’s an episode that actually explores who Graham is, why he’s here, and the grief he’s experiencing, all of which we get little bits of throughout the show, but is explored better in spinoff media, such as this and the novel, ‘The Maze of Doom.’ The alien threat isn’t super memorable, but the interaction at the end more than makes up for their interaction at the end of ‘Can You Hear Me?’