It doesn't take long to figure out who "the infant" is in this powerful film by Jean-Pierre and Luc Dardenne. Jérémie Renier plays Bruno, a petty thief who lives moment to moment selling whatever he can get his hands on and then immediately spending the money on whatever catches his eye. He's completely impulsive, selfish, and childlike. He only places value in his own immediate needs.
But Bruno has a love in his life - Sophie. And the love they share is the one force pulling against his persistent selfishness. And then there's their nine day old baby - Jimmy. The weight of this fact has not settled on Bruno in any real way. To him, their child is like a novelty item - linked to the owners only by material possession. So naturally, when the situation presents itself, Bruno sells young Jimmy on the black market to an adoption ring for a hefty sum.
This isn't much of a spoiler as this plot point is used on the back of the DVD in a summary of the film. The film isn't about this one event as much as it is about an immature and highly flawed person realizing the weight of his sin and desperately trying to claw his way toward redemption.
The direction and acting were amazing (notice the music as well). This is the type of film that gets me excited about watching more movies (there are many that do the opposite).