Professor Poponof, an old scientist, has just discovered a truth serum. Amédée, a burglar who has been surprised in his apartment, will become the perfect guinea-pig for testing the prof's last find. And it works well. Too well in fact, for if Amédée tells the truth he tells it to everybody and in every circumstance, thus causing disasters around him.
| Actor | Role |
|---|---|
 Robert GoupilNot listed | Not listed |
 Alice TissotNot listed | Not listed |
| GGéo LastryNot listed | Not listed |
 Henri CharrettNot listed | Not listed |
| PPaul ChartrettesNot listed | Not listed |
| LLéo DavidNot listed | Not listed |
| MMarcelle DemarneNot listed | Not listed |
 Clary MonthalNot listed | Not listed |
| RRégine ParisNot listed | Not listed |