Trunchbull that is so interesting.
So.
Ian and Emily's car breaks down.
The garage recommends Hotel Eden, proprietors Sylvie and Alain Deloix.
As Ian, Emily and Ollie arrive Alain Deloix is about to leave for a meeting.
Ollie disappears.
Ian finds out that Vincent and Ian know each other because they share child abuse material. Ian describes Georges Deloix (police chief/mayor) as his "mate" and implies that Georges does him favours or protects him.
Sometime between 2006 and present day Alain Deloix dies.
In the present day Georges Deloix complains that the town has suffered due to being associated with Ollie's disappearance and that he can't see his niece as often (Alain and Sylvie's daughter?).
I think that Monique is Molly, partly because that episode is called "Molly". But other possibilities that would connect her to the plot are Georges' niece or Baptiste's daughter, Sarah. Baptiste and his wife have not seen her for a while so she might have cleaned up?