Dead Space 3 is coming out early next year—think February—which should give you plenty of time to catch up on the story in Dead Space and Dead Space 3. If you didn't get one of the survival horror games in your stocking, you can pick them both up on Steam right now for a combined price of $20. Much like in a cult, it's hard to say no.
But if you're too scared to experience the first two games, or you just need a refresher, you can watch this catch-up video straight from the official source. EA and Visceral's satire of Scientology is compelling, if not entirely realistic—or so we hope.