Halliday is at a high-school dance being held in a large gymnasium. He’s surrounded by teenagers whose clothing, hairstyles, and dance moves all indicate that the time period is the late 1980s. * Halliday is dancing, too—something no one ever saw him do in real life. Grinning maniacally, he spins in rapid circles, swinging his arms and head in time with the song, flawlessly cycling through several signature ’80s dance moves. But Halliday has no dance partner. He is, as the saying goes, dancing with himself.