Jack knows the woman sitting next to him on his business flight - he just can't figure out how he knows her. Clara isn't in Jake's line of work and didn't go to college with him. They have nearly nothing in common apart from a deep and shared certainty that they've met before. This is the story of what happens to Jake and Clara after they get off that plane, and the manipulative figure who has brought them together decades after they first met.
Intensely creepy.