In a run-down apartment complex, eleven-year-old Tim endures being teased by his older brother Steven as they try to sleep on a fold-out couch. Uncle Frank, the boys’ reluctant guardian, threatens to beat them if they leave the house while he is gone for the night. As he does every night, Frank takes the vicious pit-bull he keeps chained outside the door with him and leaves. Monica, Tess, Andrew, and Rafael are on hand for this assignment, but Rafael notes they may need someone else’s help, someone who, unlike themselves, actually knows what it is like to be a child and have to fight to survive.

The next morning, Frank returns with the dog and prepares to sleep on the same couch as the boys go to school, demanding them to come home late so he can sleep longer. After school, Steven taunts and punches Tim and won’t let him hang out with his gang of friends. Instead, Tim wanders into Tess’ gym, where Rafael and Tess train boxers. Tim, wanting to be able to beat up Steven, begins to train. Later, Tim makes friends with Andrew, the new handyman at the complex. That night Steven complains of a headache and then collapses while trying to get out of bed. Tim panics. At the hospital, Tim learns from Monica that Steven has meningitis, a disease affecting his brain, and that he will be in the hospital for quite some time.

Tim, tired of being pushed around, is glad to get a vacation from his brother. Tim gets a hooded sweatshirt from Goodwill, but a bully named Jimmy recognizes the sweatshirt as his own and forcefully removes it from Tim. This only gives Tim more incentive to train with Rafael, and he does, becoming stronger everyday. At the gym, he sees a poster of Muhammad Ali, who Tim really admires because he always won his fights. Andrew tells Tim the story of Muhammad Ali’s greatest fight: how Ali refused to fight in a war because he believed God didn’t want him to kill another man, and how, because of this, he was made to give up his boxing title.

Later, Tim sees Jimmy and, using his new skills, forces him to return the shirt. Tim learns that his brother is returning from the hospital and plans to bully Steven the way he used to bully Tim, but is surprised to find Steven in a wheelchair with constant need of Tim’s assistance. Later, Jimmy’s brother challenges Tim to a fight, and they agree to meet at Tess’ gym. Tim fights the older, bigger boy and wins, collapsing into Andrew’s arms, sobbing. Andrew tells him that God loves him, and reveals Muhammad Ali standing in the ring. Tess speaks for Ali, telling Tim that he must fight for his family. Steven and Frank love him, but they are unable to show it and don’t know how to care for each other. Tess reads Tim a poem about fighting for love, and Ali hugs Tim, telling him not to forget this. Tim returns home and confronts Frank, telling him that he loves him, but that Frank must take better care of them. Touched and wanting to change, Frank begins to cook breakfast for his family. Andrew assures Frank that guardian angels will be watching over them.