Crossover is the first novel in a series which follows the adventures of Cassandra Kresnov, an artificial person, or android, created by the League, one side of an interstellar war against the more powerful, conservative Federation. Cassandra is an experimental design - more intelligent, more creative, and far more dangerous than any that have preceded her. But with her intellect come questions, and a moral awakening. She deserts the League and heads incognito into the space of her former enemy, the Federation, in search of a new life.

On a cold spring night in 1952, a huge meteorite fell to earth and obliterated much of the East Coast of the US, including Washington, DC. The ensuing climate cataclysm will soon render the Earth inhospitable for humanity, as the last such meteorite did for the dinosaurs. This looming threat calls for a radically accelerated effort to colonize space and requires a much-larger share of humanity to take part in the process. Elma York’s drive to become the first lady astronaut is so strong that even the most dearly held conventions of society may not stand a chance against her.

Inheriting your uncle's supervillain business is more complicated than you might think. Particularly when you discover who's running the place. Charlie's life is going nowhere fast. A divorced substitute teacher living with his cat in a house his siblings want to sell, all he wants is to open a pub downtown, if only the bank will approve his loan. Then his long-lost uncle Jake dies and leaves his supervillain business (complete with island volcano lair) to Charlie. But becoming a supervillain isn't all giant laser death rays and lava pits.

Few people know the name Vesper Quill. To most folks, I’m just a lowly lab rat who designs brewmakers and other household appliances in the research-and-development lab at the powerful Kent Corp. But when I point out a design flaw and a safety hazard in the new line of Kent Corp spaceships, everyone knows who I am—and wants to eliminate me. I might be a seer with a photographic memory, but I don’t see the trouble headed my way until it’s too late. Suddenly, I’m surrounded by enemies and fighting for my life.

When half of mankind revolts and demands more opportunity, those at the top decide on a compromise: They will build the first colony ships and allow the rest to discover new worlds and start over. Twelve ships are built. The first is called the Orion. Many are eager to go, but only 100,000 are chosen for each vessel. Far from Earth, a new life awaits, and it promises the prosperity they've always wanted. But still, resistance stirs.

Colton Beck has six months to live. He works for the Angor near Los Angeles, aware that any day could be his last. The Angor arrived twenty years ago, resolved to help mankind survive, but not everyone believes their motives are honorable. When the Angor offer humanity a colony world, Colton is determined to see another planet before his final breath. He's been diagnosed with Xeno, a rare disorder that surfaced with the Angor's arrival, but he won't let this stop him.

Our universe is ruled by physics, and faster-than-light travel is not possible - until the discovery of The Flow, an extradimensional field we can access at certain points in space-time that transports us to other worlds, around other stars. Humanity flows away from Earth, into space, and in time forgets our home world and creates a new empire, the Interdependency, whose ethos requires that no one human outpost can survive without the others. It's a hedge against interstellar war - and a system of control for the rulers of the empire.

A girl named Rose is riding her new bike near her home in Deadwood, South Dakota, when she falls through the earth. She wakes up at the bottom of a square hole, its walls glowing with intricate carvings. But the firemen who come to save her peer down upon something even stranger: a little girl in the palm of a giant metal hand.

Rhode Island, 1846. Estranged from his family, writer Merritt Fernsby is surprised when he inherits a remote estate in the Narragansett Bay. Though the property has been uninhabited for more than a century, Merritt is ready to call it home—until he realizes he has no choice. With its doors slamming shut and locking behind him, Whimbrel House is not about to let Merritt leave. Ever.

Leiyn “Firebrand” is no stranger to a fight. A brash ranger of the Titan Wilds, she takes up her bow to ward against the colossal spirit creatures known as titans, ever a threat to the colonies she has sworn to protect. But no amount of skill can guard against treachery. When tragedy strikes the rangers’ lodge, Leiyn vows to avenge the fallen. But if she is to succeed, she must embrace a power within her she has long denied. Power to move mountains and rivers. Power over life and death.

Get ready to experience two more origin stories in the Backyard Starship universe.

Joe Colsco boarded a flight from San Francisco to Chicago to attend a national chemistry meeting. He would never set foot on Earth again. On planet Anyar, Joe is found unconscious on a beach of a large island inhabited by humans where the level of technology is similar to Earth circa 1700. He awakes amid strangers speaking an unintelligible language and struggles to accept losing his previous life and finding a place in a society with different customs, needing a way to support himself and not knowing a single soul.

On a little-known planet, Archmage Varic Vallenar casts a grand spell to empower himself with the magical abilities of his alternate selves. The ritual works too well, granting Varic not only the magic but also the memories from six lives. Including their gruesome deaths. Now, Varic has power greater than any wizard in galactic history, but he knows that won’t be enough. The enemies he faced in those alternate lives were apocalyptic in scale. Terrors of technology and magic. Nothing that he, or anyone, can defeat.

They’ve watched us for centuries through the Rift. They’ve prepared. Invasion is inevitable. The Earth Fleet has known of the Watchers for years, unwilling to share the knowledge with humanity. Now it might be too late. Hidden away from the Fleet, one man is creating a new colony ship destined for the other side of the Rift, but he’s missing a few pieces. Three other people have varied paths to get there. Ace goes from the streets of Earth to the Fleet training facility on the moon. Flint, an ex-Fleet pilot, must decide if a job is worth his life.

Birdie Binkowitz is just a little bitter. As a young actress, she was the toast of Hollywood, definitely destined for greatness. Then the dragons had to rise up from their thousand-year slumber, take over Earth and ruin everything. Twenty years later, Birdie is living her worst life in her hometown of Tuscaloosa, Alabama, working at her father's Seed and Feed (and Bagels). Then, a mysterious dragon appears in front of the store seeking her help. He’s got a bone to pick with his fellow dragons–and he wants to hit them where it hurts.

Seventeen-year-old Ryn Whittaker is a Citadel: an elite, enhanced soldier specially chosen to guard a Rift, a mysterious and dangerous portal to alternate Earths scientists cannot control or close. Trained from the age of 14, Ryn can run faster, jump farther, and fight better than a Navy SEAL - which is good when you’re not sure if a laser-wielding Neanderthal or an axe-wielding Viking is trying to make it through the Rift and into your world. But the teenager’s military conditioning and education have not prepared her for the boy who crosses through.

When 16-year-old Kyra Agnew wakes up behind a Dumpster at the Gas 'n' Sip, she has no memory of how she got there. With a terrible headache and a major case of déjà vu, she heads home only to discover that five years have passed…yet she hasn't aged a day. Everything else about Kyra's old life is different. Her parents are divorced, her boyfriend, Austin, is in college and dating her best friend, and her dad has changed from an uptight neat-freak to a drunken conspiracy theorist who blames her five-year disappearance on little green men.

In an all-too-plausible future where corporate conglomerates have left the world’s governments in shambles, anyone with means has left the polluted Earth for the promise of a better life on a SpaceTech-owned colony among the stars. Maité Martinez is the daughter of an Earther Latina and a powerful Aunare man, an alien race that SpaceTech sees as a threat to their dominion. When tensions turn violent, Maité finds herself trapped on Earth and forced into hiding.

Two days before the start of her junior year, 17-year-old Janelle Tenner is hit by a pickup truck and killed - as in blinding light, scenes of her life flashing before her, and then nothing. Except the next thing she knows, she's opening her eyes to find Ben Michaels, a loner from her high school whom Janelle has never talked to, leaning over her. And even though it isn't possible, she knows - with every fiber of her being - that Ben has somehow brought her back to life.

Joey Harker isn't a hero. In fact, he's the kind of guy who gets lost in his own house. But then one day, Joey gets really lost. He walks straight out of his world and into another dimension. Joey's walk between the worlds makes him prey to two terrible forces: armies of magic and science who will do anything to harness his power to travel between dimensions.

All Violet wants is to be with Lincoln. But he has a secret so great it could tear them apart. Then there’s Phoenix. He’s intense and enigmatic, but he's always there for her. Caught up in a battle between light and dark - where angels seek vengeance and humans are warriors - Violet must decide who she’s willing to sacrifice and who to trust, because the wrong choice could cost her not only her life, but her destiny.

Eli knows corruption runs deep within the compound. It's a reality he's forced to confront every year on Bid Day. But when your job is to go out into the radiation-soaked Fringe so that others can live in peace, you don't ask too many questions. For Harper, the bid system works just fine. She's the best developer in her year, and she's confident she'll find a place among the wealthy, respected Systems workers. But when an upset in the bidding changes the course of Harper's future, she'll be forced to rely on an unlikely ally.

My name is Landon Hamilton. Once upon a time I was a twenty-three year old security guard, trying to regain my life after spending a year in prison for stealing people's credit card numbers. Now, I'm dead. Okay, I was supposed to be dead. I got killed after all; but a funny thing happened after I had turned the mortal coil...

Kat Dubois is immortal, and she's retired. She's long since hung up her sword and left assassinating immortals to someone else...anyone else. She's now a hard drinking, sass-flinging Seattle tattoo artist with the innate ability to read people's fortunes using her charmed deck of tarot cards. Her days of bloodshed are over, and she has nothing but time - an eternity, in fact - to hide from her past. Until someone from her past shows up on her doorstep with news that her beloved older brother and mentor, Dominic, has gone missing.

When Freedom Airlines flight 121 went down over the Pacific Ocean, no one ever expected to find survivors. Which is why the 16-year-old girl discovered floating among the wreckage - alive - is making headlines across the globe. Even more strange is that her body is miraculously unharmed and she has no memories of boarding the plane. She has no memories of her life before the crash. She has no memories period. No one knows how she survived. No one knows why she wasn't on the passenger manifest.

Can humanity Survive what it never saw coming? On October 15 at 2:15 a.ms Earth vanished. A scattered few woke alone in a world with no rules, other than survival at any cost. A journalist wanders the wretched reality of an empty New York, searching for his wife and son. A serial killer must hunt in a land where prey is now an endangered species. A mother shields her young daughter from danger through every terror-filled breath.

Meet Roya Stark. She drowns every night in her dreams, spends her hours reading classic literature to avoid her family's ridicule, and is prone to premonitions - which are becoming more frequent. And now her dreams are filled with strangers offering to reveal what she has always wanted to know: Who is she? That's the question that haunts her, and she's about to find out. But will Roya live to regret learning the truth?

Matilda Case isn't like most folks. In fact, she's unique in the world, the crowning achievement of her father's experiments - a girl pieced together from bits. Or so she believes. That is, until Abraham Seventh shows up at her door, stitched with life thread just like her and insisting that enemies are coming to kill them all. Tilly is one of thirteen incredible creations known as the galvanized, stitched together beings who are immortal and unfathomably strong.

A year ago Millie lost her legs and her filmmaking career in a failed suicide attempt. Just when she's sure the credits have rolled on her life story, she gets a second chance with the Arcadia Project: a secret organization that polices the traffic to and from a parallel reality filled with creatures straight out of myth and fairy tales. For her first assignment, Millie is tasked with tracking down a missing movie star who also happens to be a nobleman of the Seelie Court.

Mara Dyer believes life can't get any stranger than waking up in a hospital with no memory of how she got there. It can. She believes there must be more to the accident she can't remember that killed her friends and left her strangely unharmed. There is. She doesn't believe that after everything she's been through, she can fall in love. She's wrong.