Just to Be Sure

Erwan, an unshakeable mine-clearing expert, suddenly loses his footing when he learns that his father is not his father. Despite all the tenderness he feels for the man who raised him, Erwan discreetly sets out to learn more about and to find his father. He turns out to be an elderly and very endearing man named Joseph, who Erwan becomes fond of.
As good things come in pairs, Erwan crosses paths with the elusive Anna, who he undertakes to seduce. But one day when he pays Joseph a visit, Erwan realizes that Anna is in fact his half-sister. This bomb is even harder to defuse because his adoptive father now suspects that Erwan is hiding something from him.