A peaceful weekend of music and art turns sour for Miss Mallard and Willard when a famous masterpiece is stolen. Clues found all over the city point the finger at one suspect: the great Spanish artist, El Ducko. But El Ducko is one of Miss Mallard's dearest friends and she can't believe he is responsible. She takes it upon herself to prove his innocence, retrieve the stolen masterpiece, and capture the real villain, all before the museum closes at six o'clock or as she discovers, it will be too late.

The great artist and Miss Mallard's long time admirer, El Ducko, welcomes Willard and Miss Mallard to the Flamenco Festival in Spain. When Miss Mallard learns that one of El Ducko's masterpieces was stolen from his art dealer's home, she and Willard take on the case. They soon learn the painting was not stolen because of its value, but because it reveals the location of a notorious gang's hideout. The gang is arrested, but the leader and the actual painting remain missing until Miss Mallard and Willard reveal the true identity of the art thief.