Cobb can invade people's dreams, so corporations hire him to steal business secrets from rivals' subconscious. Saito, an energy magnate, wants Cobb to do the reverse: not take information, but plant an idea in a rival's mind. In return, he'll fix problems with the US government so Cobb can return to his children. Cobb takes the near-impossible job, planning three layers of dreams within dreams for the mark. It requires a larger team taking a powerful sedative: if something goes awry, the dreamers may not awake. Cobb doesn't tell his team that his past nurtures feelings powerful enough to bring on this comatose state for all of them.
