2/6 The Daleks have conquered Earth. Susan and Barbara have to join the human resistance.
1/6 The TARDIS lands in a ruined London in the 22nd Century. Daleks patrol the river!
3/3 Barbara has been infected by the deadly insecticide but keeps her condition secret.
2/3 After witnessing Forrester murder Farrow, the Doctor and Susan are trapped in a plughole.