The Mark on the Door / The Flickering Torch Mystery

Thieves keep stealing secret scientific formulas. The Hardys must solve the disappearance of a criminal informant.

English

Originally Aired December 6, 1969
Runtime 22 minutes
Network ABC (US)
Production Company Filmation Associates
Created June 16, 2022 by
SherbertKing
Modified June 16, 2022 by
SherbertKing