Margaux's half-brother, the devious and dashing Gideon, make an appearance in the season three finale. And he's sticking around for season four (it's just a formality that ABC hasn't announced one yet). But be warned: he has a dark side.
Margaux's dad, Pascal Marshal (played by Olivier Martinez), will surface on the March 23rd installment titled "Disgrace". Check out the photos here.
The casting news was first reported by E! Online.