Finding the fourth segment of the Key to Time was simple enough, but holding onto it may be another matter. The Doctor and Romana find themselves embroiled in the political games of the planet Tara, where doubles, android or otherwise, complicate the coronation of Prince Reynart.
Stargate: Continuum (2008)
Ba'al travels back in time and prevents the Stargate program from being started. SG-1 must somehow restore history.
Primer (2004)
A group of fledgling inventors discover a complex method to manipulate reality. At first, they successfully game the stock market with it, but the consequences of the invention start to catch up with them.
James vs. His Future Self (2019)
When an uptight time-travelling obsessed young scientist is visited by his nihilistic future self, he's told that he needs to give up his dream of becoming the world's first time traveler, or else. But when he won't go along with the plan, it becomes a wicked battle of man versus himself - literally.
I'll Follow You Down (2013)
After the disappearance of a young scientist on a business trip, his son and wife struggle to cope, only to make a bizarre discovery years later - one that may bring him home.
Needle in a Timestack (2021)
Nick and Janine live in bliss until her ex warps time to try to tear them apart by using Nick's old girlfriend. As Nick's memories and reality disappear, he must decide what he's willing to sacrifice to save -- or let go of -- everything he loves.
The Butterfly Effect 2 (2006)
After his girlfriend, Julie, and two best friends are killed in a tragic auto accident, Nick struggles to cope with his loss and grief. Suffering from migraine-like seizures, Nick soon discovers that he has the power to change the past via his memories. However, his time-traveling attempts to alter the past and save his one true love have unexpected and dire consequences.
Time Freak (2018)
Stillman, a heartbroken physics student, builds a time machine when his girlfriend breaks up with him. Going back in time, he attempts to save their relationship by fixing every mistake he made—while dragging his best friend along in the process.
Terminator 2: Judgment Day (1991)
Set ten years after the events of the original, James Cameron’s classic sci-fi action flick tells the story of a second attempt to get rid of rebellion leader John Connor, this time targeting the boy himself. However, the rebellion has sent a reprogrammed terminator to protect Connor.
Terminator 3: Rise of the Machines (2003)
It's been 10 years since John Connor saved Earth from Judgment Day, and he's now living under the radar, steering clear of using anything Skynet can trace. That is, until he encounters T-X, a robotic assassin ordered to finish what T-1000 started. Good thing Connor's former nemesis, the Terminator, is back to aid the now-adult Connor … just like he promised.
Broken Heart of the 56th Year (2020)
Apprentice chef Saori Nakagawa suddenly travels to Tokyo in 1964 to meet Ryuichi Kikuchi, a cook. From Kikuchi who devotes himself to cooking, Saori learns what is really important. The love of two people over 56 years.
Doctor Mordrid (1992)
Bound by hate and a mystical amulet that holds the powers of life and death, two immortal wizards meet for the last time in an ancient struggle of good versus evil.
Doctor Who: The Keeper of Traken (1981)
The Doctor and Adric learn from the wizened Keeper of Traken that a great evil has come to his planet in the form of a Melkur - a calcified statue. The Keeper of Traken is nearing the end of his reign and seeks the Doctor's help in preventing the evil from taking control of the bioelectronic source that is the keystone of the Traken Union's civilisation.
Doctor Who: Logopolis (1981)
After an encounter with the Master, an airline stewardess named Tegan Jovanka becomes an unwitting stowaway aboard the TARDIS as it travels to the planet Logopolis. There, the Doctor discovers that the Master's interference with the Logopolitans' advanced mathematics has unleashed a wave of entropy which threatens to consume the entire universe.
Clockmaker (1998)
Fourteen-year-old Henry and his friends are about to change history. Sneaking into the apartment of an eccentric Clockmaker, the kids discover that the old man controls time for the entire world through an incredible array of magnificent timepieces and weird machines. When one of the curious kids accidentally pushes a wrong button and gets launched back in time, the space-time continuum is severely disrupted. As everything begins to change around them, the young adventurers must travel back in time to save their friend...and the future
Trancers (1984)
Angel City trooper Jack Deth is sent back in time from 2247 to 1985 L.A. to inhabit the body of his ancestor. Deth's assignment is to find his archenemy, Whistler, who turns people into zombies, before the fiend is able to kill all the ancestors of the future's governing council.
Twelve Monkeys (1995)
In the year 2035, convict James Cole reluctantly volunteers to be sent back in time to discover the origin of a deadly virus that wiped out nearly all of the earth's population and forced the survivors into underground communities. But when Cole is mistakenly sent to 1990 instead of 1996, he's arrested and locked up in a mental hospital. There he meets psychiatrist Dr. Kathryn Railly and the son of a famous virus expert who may hold the key to the Army of the 12 Monkeys; thought to be responsible for unleashing the killer disease.
Back to the Future (1985)
Eighties teenager Marty McFly is accidentally sent back in time to 1955, inadvertently disrupting his parents' first meeting and attracting his mother's romantic interest. Marty must repair the damage to history by rekindling his parents' romance and - with the help of his eccentric inventor friend Doc Brown - return to 1985.
Donnie Darko (2001)
After narrowly escaping a bizarre accident, a troubled teenager is plagued by visions of a large bunny rabbit that manipulates him to commit a series of crimes.