I decided to see how many sci-fi tropes I could jam into one piece. This is what I came up with.
Form as Science Fiction
On Moon Base Alpha, Nuevo Terra-Eden, or colony ship Bieber Uno (piloted by a sentient A.I. that secretly lusts after or wants to kill the ship's captain), an impending extinction level event threatens. The sun dies, or goes supernova. Psychopathic space zombies (braaaains), space pirates (arrrgh), or zombie space pirates (braai-rrghs) lurk nearby. A newly-discovered loophole in physics unwinds the universe, a degradation of quantum mechanics makes time travel possible, or the call of a great slumbering beast from another universe fills the solar system (rawr).
Enter Jacob, who discovers the dying sun, incoming asteroid, lurking space zombies, or wormhole. Jacob tries to warn the endangered. Exit Jacob in a fiery, crushed, bloody, or physics-defying death.
Enter Steve, who emerges from or happens upon the wreckage of Jacob's mechsuit, spaceship, or bio-dome. If Steve is a child, ze may find the wreckage while playing in a cornfield in zis Midwestern hometown.
Only Steve can save the ship, town, or planet. Steve who exudes Steve-ness over bravado punctuated with punchy one-liners. Steve is female, bi-sexed, tri-sexed, or un-sexed (robot). Steve is not a sex-bot, so put your pants back on.
Steve has a flaw (or flaws). Ze may lust after the A.I. piloting the ship, be hiding a terrible secret, or suffer from an extreme phobia and/or shortcoming. A fear of commitment to the previously mentioned lusty, killer, or lusty killer A.I. qualifies as both phobia and flaw.
Jacob's death awakens Steve's drive to seek vengeaaaaaance (shouted with one fist in the air), justice (shouted while smashing a fist into an open palm), or the company of an incredibly promiscuous extraterrestrial sex goddess (murmured with one had down zis pants).
A less emotional or child Steve might seek to prevent the pandemic or invasion that only ze knows is coming, or to understand what or who killed Jacob. Adults will discount and dismiss child Steve's evidence and warnings since ze is just a kid. However, child Steve's preternatural intelligence, secret heritage, or brobdingnagian vocabulary will offset this encumbrance.
Steve's seeks The Item. Ze pursues this algorithm, key to another dimension, or macguffin with abandon. Whatever it is, The Item will come in handy later.
Enter Grevkin, who wants to rule or destroy the galaxy, kill everyone with two or more vowels in their name, clone himself, or simply profit.
Grevkin might be Steve's twin, father, or ex-lover. If so, Grevkin's ego, a broken promise, or the death of their home planet drove them apart. Grevkin vowed to hate Steve forever and now controls a giant evil corporation, a band of scrappy rebels, or an entire government.
As evidence that Grevkin lacks morals and/or is a sociopath, he throws a henchman out an airlock, kills a space puppy, or shoots an innocent. They die in the cold vacuum of space, in the belly of Grevkin's pet monster, or on the bridge.
Battle begins. Chaos ensues. Space-splosions, planetary destruction, and/or the rending of space and time decimate the solar system.
Grevkin says, "It has begun." (dum-dum-dummmmm)
Despite the destruction, Steve's plan seems to be succeeding. Except Steve's phobia, Grevkin's back-up plan, or a rouge comet/solar flare interferes.
Grevkin celebrates Steve's failure while Steve runs low on air in zis leaking space suit, can't get back to the shuttle doors on time, or is trapped in a parallel dimension. (Oh no.)
Steve records a farewell message for zis family, questions zis faith, or longs for the Midwestern corn town where ze grew up. In a last-ditch effort, Steve prepares to sacrifice zis own life to save the city, planet, galaxy, or horny sentient A.I.
But, before Steve dies, ze remembers The Item. A previously unmentioned tiny parachute in Steve's spacesuit deploys as Steve re-enters Earth's atmosphere, Steve's status as the one true genius or alien love child lets zim solve the universe, or Steve uses the interdimensional wormhole key to start the fusion reactor drives on Beiber One.
Steve defeats Grevkin, bringing down the evil corporation, closing the rift in space time, or taking control of Grevkin's spaceship. Grevkin suffers. The army of robot zombies feasts on his braaaains, a shadowy group in a darkened conference room leaves him to die, or he spins into the empty black cosmos.
Steve flies off into the next galaxy, returns to the Midwestern corn town, or is finally reunited with Bieber One. The settlement, colony ship, moon base, or planet is saved.
Adult Steve gets the girl, boy, robot, horny killer A.I., or promiscuous extraterrestrial sex goddess.
Child Steve gets a space pony.
That is, unless Grevkin goes back in time, the evil board room thaws Grevkin's clone, it was all a dream, or Luke, I am your father.
In that case, Steve's work is never done.