Returning from their adventure in medieval England, the Doctor and Sarah Jane are bewildered to find London deserted and under martial law. Even more startling is the sudden appearance of a Tyrannosaurus Rex in the street. When they reach UNIT headquarters, they learn from the Brigadier that the city had to be evacuated when dinosaurs began appearing all over London. This video features over two hours in color, but Episode 1 is in black-and-white.