Linx is providing advanced weaponry to Irongron and his men.
Hal shoots the ax out of Irongron’s hand, allowing the Doctor to escape. The Doctor is able to convince Sarah and Edward that he was trying to stop Linx, and agrees to help construct a defense against an attack on Wessex Castle by Irongron’s men.
The next morning, the robber baron and his troops assault the castle using rifles supplied by Linx, scarcely fooled by dummies the Doctor has made to make it appear as though the castle has more soldiers than they do. As they march forward, the Doctor unleashes smoke bombs, which scare them away. The failure further sours the relationship between Linx and Irongron, which has deteriorated since the robot knight fiasco and the point at which the robber saw the Sontaran’s true visage beneath his helmet.
The Doctor now decides to lead an attack on Irongron’s castle, and he and Sarah enter dressed as friars. He offers to help Linx if he sends the scientists back home, but Linx refuses and zaps the Doctor.