Nostalgex: a drug that stimulates memory. In small doses, a person can remember the order of a deck of cards. In larger doses it allows the user detailed access to their past, to focus on previously unnoticed details. On New Year's Day, Jess and Cooper's worlds collide. They must work together to look into their pasts to uncover what really happened on that fateful New Year's Eve. But what they find is that everything is a lieâŠ