Synopsis: The Doctor is noticed almost immediately by the disembarking Quarks. Looking for a place to hide, he runs into the castle in front of him. There he finds solace in (as should be no surprise to any Doctor Who fan) a network of corridors. While he is able to thin down the approaching fleet of Quarks by forcing them to split up to search the various corridors, he moves too quickly in unfamiliar territory and falls down a flight of steps. In so doing, he hits his head and is knocked unconscious.
Just as a Quark takes aim to shoot him dead, what seemed to have been a suit of decorative armor moves. The axe that accompanies the suit of armor falls on the killer Quark.
As the Doctor comes to, the person inside the armor takes off his helmet, revealing none other than James Robert MacCrimmon. The Doctor is utterly gobsmacked. He asks his former companion how he came to be in this castle. But for once it's the companion's turn to say, "I'll explain later". Jamie drops his armor and the pair are off running away from the enemy again, just like old times.