Engineer Quiller has become rich by selling his completely indestructible shop-window glass to jeweleries around the world. But this got him lots of enemies too: the insurance agencies, who've lost hundreds of customers, and the burglarers. When he temporarily looses his memory and voice in an accident, of all people, a family of thieves finds and cares for him - believing he's a pocket-picker. Things get complicated when he falls in love with his host Tilli.
| Actor | Role |
|---|---|
 Adriano CelentanoIngegner Quiller | Ingegner Quiller |
 Eleonora GiorgiTilli | Tilli |
 Pippo SantonastasoIspettore | Ispettore |
 Olga KarlatosPetula | Petula |
 Memo DittongoMomo, fratelli di Tilli | Momo, fratelli di Tilli |
 Gino SantercoleLeo | Leo |
| JJohn SharpBenny | Benny |
| GGianni Zulloil nonno di Tilli | il nonno di Tilli |
 Sandro Ghianiil barista | il barista |
 Sergio Tardioliistente del commissario | istente del commissario |
 Walter Valdiil medico | il medico |
 Dino Cassioun ladro | un ladro |
 John Karlsenil notaio | il notaio |
 Renzo Palmeril cardinale Zio | il cardinale Zio |
 Pietro Tordiil carcerato che legge la poesia | il carcerato che legge la poesia |
 Ania PieroniMaggie | Maggie |
 Gianrico Tondinelliamante di Petula | amante di Petula |