While reviewing pictures of the planet Jupiter, astronomer Jennifer Dreiser (Joanna Miles) discovers a new comet streaking through space. The joy of finding the comet is short-lived, however, when it is determined that it may hit the Earth in just eight days. Dreiser is summoned to see the President (Andrew Duggan) at his vacation home, along with a number of other experts, to discuss the situation. Astronomer Jason Voight (Richard Crenna), a specialist in near-Earth objects, shocks the group by telling them that the comet will hit within 50 miles of Phoenix. Voight urges the President to order an evacuation of Phoenix and the surrounding area, but the President ultimately leaves that decision in the hands of Arizona's governor, Michael Ritchie (Nicolas Coster). The President does order the MIRV nosecone of a Minuteman ICBM be launched into space aboard a Titan-Centaur rocket, so that an attempt can be made at destroying the comet.
In post-apocalyptic Columbia, a group of survivors led by Uri and the elders are organized as a tribe, in a primitive society without technology and lives in a small village in the Grey Rock National Park surrounded by beasts that transmit a disease that transforms the victims into mutants. Uri's son Savan is the best hunter of their tribe and successor of his father, while Kaleb is the best tracker. Kaleb and his sister Miru (Eleanor Tomlinson) are the only literate survivors. Their father Jaret believed other survivors might exist outside the park and encourages them to investigate this. Kaleb, a dreamer, is secretly in love with Savan's woman, Dorel. When the beasts attack Uri's hamlet, a group runs to a cave and blocks the entrance with logs. Kaleb saves Dorel from a beast, at which point they become romantically involved while Savan looks on.
In the near future, the cloning of animals and human organs has become routine. Cloning entire humans, however, is prohibited by what are known as "Sixth Day" laws. Billionaire Michael Drucker, owner of cloning corporation Replacement Technologies, hires charter pilot Adam Gibson and partner Hank Morgan for a ski trip. Due to Drucker's prominence, the two must first undergo blood and eye tests to verify their aptitude. On the day of Drucker's arrival, Adam finds that his family dog Oliver has died, and Hank offers to fly Drucker instead to allow Adam time to have the pet cloned. After visiting a "RePet" shop, he remains unconvinced.
The story begins with an adult Frank Walker telling an off-screen audience about his attendance at the 1964 New York World's Fair as a child. In the flashback, he meets David Nix, an official who is unimpressed with Frank's limited jet pack. Frank does draw the attention of a young girl named Athena. Seeing his potential, Athena gives Frank a pin embossed with a "T" symbol and tells him to follow her aboard the fair's "It's a Small World" attraction. Frank sneaks onto the ride, where his pin is scanned and he is transported into a futuristic cityscape known as Tomorrowland. He falls from a ledge, but straps on his jet pack and lands safely before Nix and Athena.
The United States has lost the war on drugs. Substance D, a powerful and dangerous drug that causes bizarre hallucinations has swept the country. Approximately 20% of the total population is addicted. In response, the government has developed an invasive, high-tech surveillance system and a network of undercover officers and informants.
Patty Jo Myers is a young woman who considers herself a Christian because she occasionally reads her Bible and goes to church regularly. She refuses to believe the warnings of her friends and family that she will go through the Great Tribulation if she does not accept Jesus. One morning, she awakens to find that her family and millions of others have suddenly disappeared. Gradually, Patty realizes that the Rapture, an event some interpret from the Bible, has happened and she and everyone else left behind are entering into the Great Tribulation, the last days of Earth, dominated by the Antichrist. A government system called UNITE (United Nations Imperium of Total Emergency) is set up and those who do not receive the mark identifying them with UNITE will be arrested. Patty desperately tries to avoid the law and the mark but is captured by UNITE. Patty escapes but is cornered by UNITE on a bridge, and falls from the bridge to her death.
In the 23rd century a reconnaissance starship discovers a dead alien spaceship of unknown origin in deep space. The crew are found to be humanoid bodies, made by an advanced cloning process. One humanoid woman appears to be alive but has memory loss and is brought back to Earth. Scientist Sergei Lebedev settles her in his own house and names her Niya.
In the late 21st century, global warming has flooded coastlines, drastically reducing the human population. There is a new class of robots called Mecha, advanced humanoids capable of emulating thoughts and emotions. David (Haley Joel Osment), a prototype model created by Cybertronics of New Jersey, is designed to resemble a human child and to display love for its human owners. They test their creation with one of their employees, Henry Swinton (Sam Robards), and his wife Monica (Frances O'Connor). The Swintons' son, Martin (Jake Thomas), was placed in suspended animation until a cure can be found for his rare disease which is caused by the Sinclair virus. Initially frightened of David, Monica eventually warms enough to him to activate his imprinting protocol, which irreversibly causes David to have an enduring childlike love for her. He is also befriended by Teddy (Jack Angel), a robotic teddy bear, who takes it upon himself to care for David's well-being.
In the year 2000, shortly after her best friend's sudden suicide, a Japanese schoolgirl named Alice wins a competition to be the youngest person ever to be sent into space, on a semi-commercial space airline. However, something goes wrong during the flight, and the shuttle crashes, killing all on board except for Alice and the stewardess robot, SS1X. Finding themselves in a desolate, snowy landscape, they set out to find help.
In the year 2073 Nicholas Sinclair is a scientist on a time travel project. An accident introduces a deadly virus in to the past in 1973, causing a paradox. The project's automatic countermeasures activate and attack robots are sent in to the past to try to eliminate the virus carriers. They fail to contain the virus, and Sinclair returns to 2073 to find the Earth in ruins, ravaged by both the virus and the attack robots continually sent from the original timeline. Sinclair travels to the ruined project lab in the paradox timeline and uses the equipment there to travel to the original timeline and prevent the mission that caused the paradox, resolving it.
Sometime in the future, mankind has depleted all energy and fuel sources, however they have somehow engineered a way to use human excrement as fuel. To reward production, the government hands out extremely addictive, popsicle-like "Juicybars", which in turn also makes them constipated. Aachi and Ssipak are street hoodlums who struggle to survive by trading black market Juicybars. Through a chain of events involving their porn-director acquaintance Jimmy the Freak, they meet a porn star named Beautiful, whose defecations are rewarded by exceptional quantities of Juicybars. For that reason, Beautiful is also wanted by the violent blue mutants known as the Diaper Gang (led by the Diaper King), the police (most notably the cyborg police officer Geko), and others.
In 1279 A.D., the downfall of the Chola dynasty seems imminent as the Pandyas drive the Chola people out of their kingdom in southern India. To escape them and save the life of his successor the Chola emperor sends his son along with the Chola people to a secret territory. The refugees take along an idol sacred to the Pandyas, angering them. To capture the escaped Cholas and the stolen idol, the Pandyas extend their invasion to unexplored territories but cannot find them.
In the year 2022, the penal system is run entirely by corporations, with prisoners seen as assets. Highly-trained ex-marine John Robbins is imprisoned for life for murdering his commanding officer, who in 2011 ordered him to kill scores of innocent men, women and children in Benghazi (Libya). The event haunts Robbins over a decade later.
In the year 2010, a virus infected everyone on the planet, wiping out half the population. Absolon is a drug regimen everyone must now take to stay alive. One corporation controls the drug and Murchison (Ron Perlman) is its leader.