On last week's Heroes premiere, one character learned the shocking truth about his parentage. And he's hardly the first. When scifi's heroes and villains start shaking the family tree, a few unexpected branches are sure to tumble down. We collected some of science fiction's greatest genealogical curveballs. Be prepared for familial spoilers below.Kyle Reese is John Connor's Father (Terminator): In the future, Kyle Reese is one John Connor's best soldiers and closest friends. He also harbors a slightly creepy attraction to John's late mother, Sarah, volunteering to go back in time to protect her. Little does he know that his brief pre-mortem coitus with the young Sarah Connor will make him the father of the future Resistance leader. Jeffrey Spender is Fox Mulder's Half-Brother (The X-Files): Fox Mulder's already shadowy history gets even more confused when fellow FBI agent Jeffrey Spender claims to be Mulder's half-brother, a claim their similar DNA seems to confirm. It also suggests that Mulder's real father is not Bill Mulder, but the nefarious Cigarette Smoking Man. Benjamin Sisko's Mother was a Prophet (Star Trek: Deep Space Nine): Star Trek is full of surprise relatives: Kirk and David Marcus, Worf and Alexander, Picard and his clone Shinzon. But no family tree is quite as strange as that of Captain Benjamin Sisko. To bring about their emissary, the Bajoran Prophets send one of their own to possess a human woman, marry Joseph Sisko, and give birth to little Benjamin. Although biologically human, Sisko would have deep ties to the Prophets and Bajor. Quinn Mallory's Parents are Sliders from Another Dimension (Sliders): Brilliant physics student Quinn Mallory hops from dimension to dimension, hoping to find his way home. But it turns out Earth Prime is not the dimension where Quinn was born. Rather, he was born on Kromagg Prime and spirited away by his real, dimension-sliding parents. He was raised on Earth Prime by his parents' doubles, who grew so attached to Quinn that they never bothered to give him back. The Sleeper Cylons' Parents are False Memories (Battlestar Galactica): It's heartbreaking enough to find out that you're a cylon, a member of the race who has just committed genocide against your loved ones. But on top of that, you discover that your whole childhood, your whole history was a sham. For Boomer, who believed her parents died in a mining accident, it means the loss of her family a second time. Various Mutants are the Parents/Children/Clones of Other Mutants (X-Men): The X-Men, their adversaries, and their allies have family trees that rival those of soap opera characters. There are your more traditional love children you never knew existed (as with Professor Xavier and Legion, and Magneto and the twins Quicksilver and Scarlet Witch) and parents who abandoned you as an infant (as with Nightcrawler and Mystique). But when you bring in time traveling, alternate dimensions, and cloning, it's hard to keep track of who's who at the family reunion. Claire Littleton is Jack Shephard's Sister (Lost): Many of the people who find themselves on the Island are connected to one another, if only tenuously. For Claire and Jack, that tie is a common bloodline. Strangers before the crash of Oceanic 815, Jack and Claire are both the children of the dead-but-not-gone Christian Shephard. This makes Jack uncle to Claire's son Aaron, and makes Jack a bit uncomfortable with his ex-girlfriend Kate raising the boy. Bruce Wayne is Terry McGinnis's Father (Justice League Unlimited): Terry McGinnis, Bruce Wayne's protégé, always did resemble his boss more than his parents. That's because Terry was part of a Boys from Brazil-style scheme to create another Batman. Warren McGinnis's germ cells were replaced with Wayne's, making Wayne Terry's genetic father. And, when Terry experiences the outrage of his father's murder, he does take up the Batman mantle. The Comedian is Laurie Juspeczyk's Father (Watchmen): Laurie always knew that her mother's agent husband wasn't her real father. But she never suspected her father was the sadistic Comedian, who once sexually assaulted Laurie's mother, but later fathered Laurie through consensual sex. And she's not the only one who's surprised. Even Doctor Manhattan couldn't have predicted the circumstances of Laurie's unlikely birth, a thought that renews his interest in humanity. Fry is his own Grandfather (Futurama): When Fry travels to the past and encounters his grandfather, he makes it his mission to preserve the timeline and make sure his granddad stays alive. In true Fry fashion, this ensures that Grandpa Fry gets incinerated. Upon realizing he hasn't disappeared, Fry shrugs and beds his newly-widowed grandmother, thereby becoming his own grandfather. The Bartender is His Own Entire Family ("–All You Zombies–"): The Bartender has Fry beat on being his own descendant and ancestor. Through a remarkable series of events, he becomes his own mother, father, lover, and daughter. Over the course of his life, he comes to understand the loop of his own creation, but is mystified by the rest of humanity. Darth Vader is Luke and Leia's Father (Star Wars): The galaxy far, far away may be a big place, but Luke Skywalker just keeps running into people he's related to. And the revelations are bittersweet. First he learns that his father is the homicidal lunatic who just chopped off Luke's hand. Then he finds out Leia's his sister after all that quality time they spent together in Splinter of the Mind's Eye.