Five medicine interns in an old public hospital must face all their fears when they start to being stalked by a strange being.

Gastón Fernández has arrived at 34 without too much to show or brag about. He has no money, job, girlfriend, friends or life plan. He's a composer that doesn't compose. The one-time "most likely to succeed" at Santiago's Musical Conservatory has passed from promise to failure. He feels he is beginning to wander alone. Isolated and detached. Gastón feels that everyone judges him and see the word loser tattooed on his forehead. At the same time, an alter-ego, a sort of doppelgänger, haunts him.

In Santiago, Chile, the schoolteacher Luisa proposes a debate about sex with the parents of her students with the intention of giving classes about sex education to the youngsters.