This is a movie directed by Christopher Nolan, who is famous for directing Insomnia and Dark Knight.
Leonard DiCaprio acts a man named Cobb, who can sneak into one's dream(or subconcious) and steal "idea."
A major company's manager Saito, performed by Japanese actor Ken Watanabe, asked Cobb to do "inception," that is planting idea to someone.
Saito wants to break down the rival company, so he plans to carry out inception to the heir of it.
Cobb accepts the job because he wants to clear the suspicion of murdering his wife.
As the job is very risky, Cobb builds a team: his buddy Arthur, designer Ariadne, identity forger Eames, and concoctor Yusuf.
Inception requires getting into one's dream deeply.
Cobb, his associates and Saito go into three-layer dream. But Cobb's wife Mal appears and breaks in...
One of the themes of this movie is the distinction between fact and fiction.
Having suspicion in her dream that this world may not be true, Mal got a relentless anxiety. she couldn't remove it even in the "actual" world, and committed suicide.
Those who watch this movie also gets confused, "What layers of dreams are they in?" or "Does the actual world really exist?"
After I watched it, I wondered how Cobb has such a strong belief in the actual world, could tell it from fiction and resist the temptation of staying together with his wife in the dream.
So we are left to doubt if he really got back to his kids in real life or if the whole thing was actually a dream from which he never woke up.