"Foster Boy" follows Michael Trainer (Matthew Modine), a hardened corporate lawyer unwittingly dragged into an ominous trial in which a for-profit foster care agency put a known sex offender into the same foster home as his young client Jamal (Shane Paul McGhie), resulting in catastrophic trauma and immediately altering Jamal's future. He wants nothing to do with Jamal's case until a Judge forces him to represent him.

When Jamal refuses to settle the case for any amount of money, Michael begins his representation in earnest and forges a strong bond with the young man. Their work together reveals the horrifying depth of the corrupt and abusive for-profit foster care agency, as well as its blatantly racist and classist exploitations of the system, Michael is transformed from reluctant defender to fierce warrior in the battle for justice.