After receiving a flurry of messages, Davie arrive at the doorstep of someone who might just hold the key to the whole investigation.

Presenter: Davie Donaldson

Producer: Kate Bissell, BBC Scotland Productions.

Researchers: Rachael Fulton and Catrina Rose

Additional reporting: Cameron Mackay

Story consultants: Jack Kibble White and Kirsty Williams

Sound Designer: Julian Corrie

Music : Julian Corrie with additional tracks by Barry Jackson

Editor: Heather Kane Darling

With thanks to Martin Conaghan for developing the initial podcast idea with BBC Scotland Productions.