Rainbowdash wanted to explore, and have awesome adventures in faraway lands, so when Twilight offered her the opportunity to go further than any pony has gone before, she took it. Now she's stranded on an Alien planet, with no way back home, and none of her friends. But she does find some very unlikely aid.
Ryley is a survivor from the spaceship Aurora, and as far as he can tell, he might be the only one, now after just having his hopes of rescue dashed, he is suddenly confronted with a different survivor, one who might just help him find a way of this planet after all.
Together the unlikely pair now need to uncover the mysteries of why they're both here, and what else is on Planet 4546B.
A crossover with the Game Subnautica, a highly entertaining game that I seriously suggest you play before reading this, or even if you don't read this story, just play the game, its good fun.
Also spoiler warning for the game, hence why you should just go play it, done that? Good, now time for story.