Marc Dionne was last seen on September 1, 1997, in Trois-Rivières, Quebec. That evening he left the Harley Pub in the Cap-de-la-Madeleine area and was observed getting into a small white vehicle, entering on the passenger side. He did not communicate with family or friends afterward and was reported missing the next day.

Initial investigation in the hours and days after his disappearance produced no significant leads, and no confirmed sightings or contacts have been reported since. The circumstances are limited to that single evening: leaving the pub, entering the white car, then never being heard from again. The lack of contact was out of character and has left his family without answers.

Did anyone in Trois-Rivières around September 1, 1997, see Marc that night or remember a small white vehicle in the Cap-de-la-Madeleine area?