Authors Note; Let's shake the hat, one more time...
Wild Planet
Pairing: Mike Newton/Leah Clearwater.
Setting: The Future.
Complication: Time Travel.
Villain: Volturi.
Mike Newton has recently graduated from college and ended the relationship of three years he had with a girl he met as a Sophomore. He is returning to Forks for the summer, before he starts his new job, which is based on his new degree and up to the author. It might not even be mentioned, if you can spin it. Anyway, he goes back home and relaxes for a few days, hanging out with his old friends, like Jessica and Tyler and so on. Then, thanks to years of working in his parents store, he decides to go on a hike. His friend, who was supposed to join him, begs out at the last minute and he decides to go on his own, anyway.
A few miles away, in La Push, an angry and annoyed Leah Clearwater is still living on the reservation, despite hopes to someday get out of there. She is helping out her mother at the hospital, after training to be a nurse and is still trying to move on from Sam, who is now married to Emily and maybe has some kids, too. She is also desperately trying to stop phasing, so she can grow old, die and escape her painful past and current life. Up to you if canon Twilight through BD happened, but Leah, for some reason, is still stuck in La Push, whether she's in Jake's pack or Sam's. Just keep her there, in the beginning.
Anyway, Mike is out hiking, when he gets hurt and is unable to move or go anywhere and of course, he didn't bring his phone with him, or its battery is flat or something, whatever. The point is, he's unable to contact someone, to tell them to get him help. Surrounded by only animals and trees, he very painfully sets up camp and hopes that somebody will come by the next day or that he will heal enough to handle the journey on his own. In the middle of the night, however, he is woken by strange noises, no idea that it is Leah in wolf-form, as she patrols the area for Vampires.
Leah should be the one to discover him the next day, or the day after that. It should be at a point where Mike is beginning to starve and maybe gangrene is setting in, in his injury. Her nursing education should somehow come into play, is what I'm trying to get across. Unfortunately, since her being a shapeshifter is a secret, she can't even carry him to the hospital, though she plays with the thought of simply knocking him out, but for some reason doesn't go that far. Also up to the author, the reason for that. Anyway, she's stuck taking care of him and she can't even phase to get help, because he won't let her get out of sight, now that he's not alone anymore.
Over the course of the time they spend in the woods, getting to know each other and trying to keep Mike as healthy as possible, the two fall in love. I always felt that Leah would be much happier, if she never imprinted, but actually fell in love the old-fashioned way. And I don't want Mike's poor heart broken, so don't have Leah imprint later, unless it's on Mike, with an explanation for why it took time to happen, thank you. Anyway, they fall in love and eventually get back to town, where everyone has worried and put up missing posters.
A few weeks more pass by, where Mike and Leah spend time together, either in La Push or Forks. If you are keeping things slightly canon, you can have them discussing their previous relationships with Bella and/or the Cullen family. Or maybe the strange disappearances in Seattle, several years earlier :)
Now, for the complication and villain, there are two ways you can go with this, according to this challenge:
1. They time travel back to a past event, depicted in one of the books, or heard spoken of in one of the books, i.e; Newborn armies in the South during the Civil War, Didyme's death, Newborn battle in Eclipse, standdown in Breaking Dawn and so on. Or, since it's an alternate universe, a battle or something that isn't actually canon, but is still 'history' in the story. The Volturi, of course, are the bad guys, but that can mean many things. They can be the reason for the time travel, the thing they have to fight in the past or something third, as long as they are the 'main' villains.
2. They time travel to the future, where the Volturi have decided to let the world know they exist. Humans either live in relative peace with the Vampires, or the world is almost decimated and humans live in factories, to be used as food source for the Volturi, the rulers of the world. If you choose this one, you could have Mike and Leah joining the resistance, beating the Volturi on their own, though that should be a pretty good reason, or something third. All I ask is no duplicates. Meaning, they go far enough into the future, that there are not two Leah's or two Mike's, thank you.
Whether they ever return to their own time, are killed off, either one or both, whether they win or lose, or have a happy ending or not... completely up to the author.
Enjoy. :D