Eight year old Lucas would like to know how the Tooth Fairy exchanges coins for teeth without getting caught. He is determined to stay awake all night to find out. Meanwhile, a little mouse falls into a trap set by a dishonest contractor who is desperate to tell the world his secret, that the mouse is the Tooth Fairy. Lucas and his family has to do everything in their power to help the sweet little mouse with its mission, which since time immemorial, is to make children happy...

David Alfaro Siqueiros, recognized Mexican muralist, travels to Argentina in the thirties with the purpose of giving a few conferences and paint a mural of revolutionary subject matter, which faces local political rejection. The press mogul head of the newspaper Critica, Natalio Botana, personal friend to the President of the Nation Agustín P. Justo, propose Siqueiros to collaborate in the cultural supplement of the diary and paint a mural in the basement of his Villa Los Granados. Siqueiros accepts and does that his wife the poet Blanca Luz Brum meets him, his arrival to Los Granados and his romance with Botana provokes the jealousies of his powerful anarchist wife Salvadora Medina Onrubia and Siqueiros himself, which turns the Villa almost in one of the scenes of the Ejercicio Plástico, how Siqueiros named his work.