The Doctor and Sarah Jane return from dinner at Medieval Times to find London deserted except for small bands of looters, under martial law, because that's what happens when Labour abandons its socialist principles and joins a coalition with the Liberal Party. Also, pterodactyls. So, instead of being arrested by UNIT for sneaking onto their base with forged credentials, SJ gets arrested by UNIT for violating curfew and probably being a looter. She and the Doctor escape and get recaptured again within only half an episode, but they escape again when a T-Rex (not the glam rock band) attacks.