Shattered Time

Anji Singh and John Colton, two Canadian University students, volunteer for
a science Time travel.
Honestly though, John was looking to make some cash for the weekend and Anji was a dreamer.
They were shocked to find time travel is possible and works.
The two unskilled, untrained, Chrononauts travel four hundred and sixty-three years into the future.
The world has changed considerably over that time.
Fifty years after their departure, a migration of alien spacecraft from a distance galaxy,
traveling through Earth's solar system, inadvertently crash into the moon and the Earth
creating massive, cataclysmic destruction.
As if that wasn't enough, two hundred and fifty years later, a second migration of ships,
following the first, also crash into the Earth creating further destruction.
Due to a power disruption, Anji and John's craft loses power and they are trapped in the
future environment, inhospitable and poisonous to them.
The inhabitants of the crashed ships have tried their best to help the remaining remnants
of humanities past using their medical technology, science, and advanced biomechanics.
Androids, aliens, robots, and mutants now cover the Earth.
Anji is anxious but ecstatic over the alien technology, hopeful to return to their time and warn others
about the future cataclysms. To save humanity, she's willing to fight (and order John around till he does too.)
John just wants to go home, and maybe, if he's lucky, have some romantic time with Anji.
Or any willing female, human or otherwise, if possible.
Meh, John's not picky.