Imagine your every move is being tracked by someone whose clear intention is to do you harm. Filmmaker Maggie MacGowen arrives at the Paris apartment she inherited from the mother she never knew, ready to begin a settled life with her fiancé, Jean-Paul Bernard. But a cryptic phone call from Jean-Paul, summoning her, begins a nightmare winter odyssey across Europe as they try to stay a step ahead of a predator who uses every electronic medium to stalk their every move. Clearly, someone wishes them harm. But who? And why? As they try to answer those questions, their unknown nemesis uses the internet to offer a reward for their capture, turning the pursuit into a crazy real-world video game with an infinite number of players and no rules.