曼城的一位警探 Sam Tyler 在办案中被车撞倒在地，从昏迷中醒来后发现自己的4×4车变成了30年前的款式，车内有把他调到曼城警署的文件。原来他回到了1973年，还是在同一栋楼里办公，成了另一个警探 Gene Hunt 的下属，Gene 是 DCI (Detective Chief Instpector)，Sam 是 DI (Dectective Inspector)，他们俩象是组长副组长的关系，手下还有几个警探，包括制服女警 Annie (WPC Woman Police Constable)。

The Doctor faces the end of his life as the Master's plans hurtle out of control. With the sound of drums growing louder, and an ancient trap closing around the Earth, the Doctor and Wilf must fight alone. But sacrifices must be made, and the deadly prophecy warns: "He will knock four times."

The Ood have given a warning to The Doctor. The Master is returning yet that is not the biggest threat. A darkness is coming which brings with it The End of Time.