On the planet Karfel a high ranking official, Maylin Tekker, uses threats against Peri to force the Doctor (Colin Baker) to go to Earth and bring back a young woman called Vena who, while holding a precious amulet, has accidentally fallen into the Timelash - a time tunnel through which the planet's tyrannical ruler the Borad banishes all rebels. The Doctor also inadvertently brings back Herbert, a man from the 19th Century, who stows away aboard the Tardis.