The entrepreneur and owner of a factory of cans Tancredo and his wife Luiza are extremely happy with the return of their only son Sérgio from Madrid, graduated in nuclear engineer. Tancredo plans a convenience marriage of Sérgio with Lucy, whose aunt owns an aluminum plant. However, Sérgio has studied music instead, and while traveling back to Brazil, the captain of the ship invites him to organize a farewell show for the passengers. Together with the steward Chico and the stowaway Mara, they present a successful concert and Sérgio invites the couple to work with him. But Madame Frou-frou is cheated by Chico and promises to revenge. In Rio de Janeiro, Sérgio introduces Chico and Mara as a Professor from the University of Ohio and his assistant, and they lure Tancredo building the night-club "Boite Atômica" as if it were a power plant. They invite the international attraction Melvis Prestes for the grand-opening. However, Madame Frou-frou discloses their scheme and they have to improvise to succeed in the show-business.