David Daker

When Rodney falls in love, he doesn't appreciate Del's brotherly helping hand.

Fletcher is desperate to get away from making fishing nets.

As the repairs to Linx's spaceship are completed and he prepares to take off, the Doctor races to save the captured scientists and to prevent the course of history being changed forever.

The Doctor discovers that the alien is Linx, a Sontaran warrior, trying to repair his spaceship. Sarah Jane is convinced that the Doctor is responsible for the scientists' abductions.

Linx is providing advanced weaponry to Irongron and his men, who are preparing to attack Sir Edward's castle. The Doctor is forced to improvise a defence, but it's unknown if it will be enough.