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, whove 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 hes a pocket-picker. Things get complicated when he falls in love with his host Tilli.