In the conclusion to the four-part story "Snakedance," the Doctor (Peter Davison) prepares for a showdown with the malignant mind-force Mara on the planet Manussa. First, however, the Doctor must find the "still point" within himself. Even if he succeeds in this, is it too late to rescue Tegan (Janet Fielding), whose mind has been enslaved by the insidious Mara? Written by Christopher Bailey, "Snakedance, Episode 4" first aired on January 26, 1983. ~ Hal Erickson, Rovi