A race of giant Gastropods has taken over the planet Jaconda. Their leader, Mestor, now intends to cause an enormous explosion in order to spread his people's eggs throughout the galaxy, and he kidnaps juvenile twin geniuses from Earth to work out the necessary mathematical equations. Space fighters led by Lieutenant Hugo Lang are dispatched to get the twins back, but they come under attack and Lang is the sole survivor when his ship crashes on the asteroid Titan III. A newly regenerated Doctor and Peri become involved and help Jaconda's elderly former ruler Professor Edgeworth, who is really a Time Lord named Azmael, to defeat Mestor and free the planet's bird-like indigenous people from the gastropods' reign of terror. Azmael, however, sacrifices his life in the process.

June and Jennifer Gibbons are twins from the only Black family in a small town in Wales in the 1970s and '80s. Feeling isolated from the community, the pair turn inward and reject communication with everyone but each other, retreating into their own fantasy world of inspiration and adolescent desires. After a spree of vandalism, the girls are sentenced to Broadmoor, an infamous psychiatric hospital, where they face the choice to separate and survive or die together.

Thirteen year old Sam Cleary suspects that his mysteriously reclusive neighbor Mr. Smith is actually the legendary vigilante Samaritan, who was reported dead 25 years ago. With crime on the rise and the city on the brink of chaos, Sam makes it his mission to coax his neighbor out of hiding to save the city from ruin.

A child is born. We see underwater swimmers representing this. He is young, in a jungle setting, with two fanciful "instincts" guiding him as swooping bird-like acrobats initially menace, then delight. As an adolescent, he enters a desert, where a man spins a large cube of metal tubing. He leaves his instinct-guides behind, and enters a garden where two statues dance in a pond. As he watches their sensual acrobatics of love, he becomes a man. He is offered wealth (represented by a golden hat) by a devil figure. In a richly decorated room, a scruffy troupe of a dozen acrobats and a little girl reawaken the old man's youthful nature and love.

Widowed Welsh mother Anna Leonowens becomes a governess and English tutor to the wives and many children of the stubborn King Mongkut of Siam. Anna and the King have a clash of personalities as she works to teach the royal family about the English language, customs and etiquette, and rushes to prepare a party for a group of European diplomats who must change their opinions about the King.

Identical twins are separated at birth, one becoming a streetwise mechanic, and the other an acclaimed classical concert conductor. Finally meeting in adulthood, they're mistaken for the other and entangled in each other's worlds.

Olivia and Matthew Grey, 18-year-old twins born into a world of privilege and high expectations. There are almost no boundaries between them - even their dreams are connected.

A trapeze artist causes the death of another over their mutual love of a girl. When a new artist joins the troupe and falls in love with her, she must protect him from her ex-lover's jealous rage.

Caio is a deeply religious young man, living in the shadow of his brother, Alberto. While Alberto challenges norms and embraces life, Caio feels trapped by his beliefs. In a moment of desperation, Caio murders Alberto and stages his death as a suicide, convincing himself that he acted in God’s name.

Ned Kendall is asked to return to the remote and isolated family home by his sister, to say goodbye to his father who is dying. Ned also brings his young aspiring actress fiancee who struggles with the isolation. When home he starts having memories of his childhood many involving his beautiful twin sister and his older brother. These memories awaken long-buried secrets from the family's past.

Jean Claude Van Damme plays a dual role as Alex and Chad, twins separated at the death of their parents. Chad is raised by a family retainer in Paris, Alex becomes a petty crook in Hong Kong. Seeing a picture of Alex, Chad rejoins him and convinces him that his rival in Hong Kong is also the man who killed their parents. Alex is suspicious of Chad, especially when it comes to his girlfriend.

Twins Ronnie and Reggie Kray are raised in east London, under the influence of their hateful but doting mother Violet. As they grow up, Ronnie's violent nature takes over, and Reggie follows his brother's lead. The two become notorious crime lords who rule over the East End club scene. But at the height of their power, the brothers veer into different lives, giving the older crime bosses a chance to reclaim what the Krays took from them.