Ep 5. Snakedance (1)

In Doctor Who season 20 episode 5, titled "Snakedance (1)", the Doctor and his companion Tegan land on the planet Manussa, where a festival is taking place to mark the 500th anniversary of the defeat of the Mara, an evil entity worshipped by a now-extinct civilization. However, the Doctor soon discovers that the Mara has not been truly defeated, and is still present in the minds of the Manussans.

Tegan, who has visited Manussa before and has a connection to the Mara, is drawn to a snake-dancer named Lon, whom she believes to be the reincarnation of a Manussan ancient hero. Meanwhile, the Doctor begins to unravel the mystery of the Mara's return, which seems to be linked to a powerful crystal that has been taken from the planet's core and is now in the hands of a group of human archaeologists.

As the festival progresses, the Doctor and Tegan become caught up in a dangerous web of illusions and dreams created by the Mara, as it seeks to use Tegan's connection to it in order to gain control over the Manussan people once again. With the help of an old friend of the Doctor's, the wise Manussan priest Dojjen, the Doctor sets out to confront the Mara and stop its evil plans.

But as he delves deeper into the mysteries of the crystal and the Mara's true nature, the Doctor begins to realize that defeating the Mara may not be as simple as it first seemed, and that he may need to confront his own demons in order to save the day.

Filled with suspense, intrigue, and unforgettable characters, "Snakedance (1)" is a classic Doctor Who adventure that explores themes of power, identity, and the nature of evil itself. With stunning visual effects, a gripping storyline, and some of the most iconic moments in the show's history, this is an episode that will keep viewers on the edge of their seats from start to finish.