In 1955, a construction worker involved in the demolition of the "J. C. Wilber Building" pries off the top of the cornerstone and finds a metal box within. The unnamed man opens the box and finds, along with a commemorative document dated April 16, 1892, a
live frog inside, who dons a top hat and cane. After the frog suddenly performs a musical number on the spot, the man sees an opportunity to cash in on the frog's anthropomorphic talents and sneaks away from the site with the frog in the box under his arm. Every attempt the man makes to exploit the frog fails: the frog performs exclusively for his owner and instantly devolves into an ordinary frog the second anyone else sees him. Remaining unaware of this reality, the man takes the frog to a talent agent. After getting kicked out over the frog's apparent inability to act, he uses his life savings to rent an abandoned theater so he can showcase the frog on his own. The frog performs atop a high wire behind the closed curtain, while the man struggles to get an audience and succeeds with the promise of "Free Beer". As the frog winds down the song, the man breaks the cord of the curtain he is trying to open. By the time the man reaches and pulls what remains of the cord, fully revealing the frog to the crowd, the frog has again reverted to his ordinary state. The angry crowd pelts the man with rotten vegetables. Following these failures, the man is now homeless and living on a park bench; there, the frog still performs only for him. When a policeman overhears the singing in the middle of the night, he approaches the man, who points to the frog as the singer. When the frog again presents himself as ordinary, the policeman arrests the man, ostensibly for vagrancy but also as insane. The man is committed to a
"Psychopathic" Hospital along with the frog, who continues serenading the hapless patient. Following his release, the now haggard and destitute man — still carrying the box with the frog inside — notices the construction site where he originally found the box. He joyously dumps it into the new cornerstone for the future "
Tregoweth Brown Building" and runs away, finally rid of what has become his burden. 101 years later, in 2056, the Brown Building is being disintegrated by futuristic demolition workers. The box with the frog is discovered again, this time by one of the 21st-century crew members. After envisioning a cash bonanza of his own, the worker absconds with the frog in the box, thus beginning the cycle anew. == Production notes ==