Alphonse and his wife Zulma hold the 421, a tavern in the outskirts of Lille, in the North of France. It is always full of regulars who play cards there and drink gin and exchange words in ch'timi, the local patois. But there has been trouble lately: felonies have been committed in the surroundings. So who can be those two strangers who have just rented a room each at the 421? Each sets about doing a bit of detective work.
| Actor | Role |
|---|---|
| EEdouard BrévilleLouis Bruxellois | Louis Bruxellois |
 Suzanne ChristyElise Brassepeninck | Elise Brassepeninck |
| LLine DarielZulma Brassepeninck | Zulma Brassepeninck |
| JJean DarwelsLe Sidi | Le Sidi |
| AAndré DuhamelJohnny Brown | Johnny Brown |
 Guy FavièresPatron Commissaire | Patron Commissaire |
| ZZizi FesteratL'agent | L'agent |
| HHélène OurgelSidonie | Sidonie |
| PPradelleDésiré | Désiré |
 Paul RobertL'homme au foulard blanc | L'homme au foulard blanc |
| WWalter RuffaxHuberto Cavelcanti | Huberto Cavelcanti |
| LLudy SambiOlga Mersmann | Olga Mersmann |
| LLéopold SimonsAlphonse Brassepeninck | Alphonse Brassepeninck |
| RRaymond VazelliHégésippe Navet | Hégésippe Navet |