She was serving meals to a table where a family of four was sitting. Three of the people—an adult male, an adult female, and a four-year-old girl—were sitting on one side, seemingly enjoying themselves. The boy was on the other side, not being spoken to and not speaking. He was the only one for whom the adults had not ordered food. Ms. Carvalho thought this was odd.

Then she noticed bruising near the boy’s eye, and a cut above his nose. And more bruising on his lower arm. She could have done nothing.

But she couldn’t just let it go. On a piece of paper, in big letters, she wrote: “ARE YOU OK?” She stood behind the table and held the paper up so only the boy, alone on the other side, could see it. He made a motion with his head. She sensed he was afraid. So she wrote another message: “DO YOU NEED HELP?”

The child nodded yes.

Ms. Carvalho thus became the first person that night to do the right thing. She went to a phone and called the owner of the restaurant, Rafaela Cabede. She said what had happened. Should she call the police?

Ms. Cabede didn’t hesitate. If Ms. Carvalho’s hunch turned out to be mistaken it could have meant trouble for her restaurant. Still, she said to call 911 right away.

Now two people had done the right thing. Ms. Carvalho called 911, told the dispatcher what she had observed and, according to the tape, said: “I don’t know what to do. Can you give me some advice?”

The 911 dispatcher, Fahad Mumtaz, did more than offer advice. He said the police were on their way.

Three people had done the right thing.

Orlando Police Officer Brett Brubaker arrived. After speaking with Ms. Carvalho he approached the table. He told the man at the table— Timothy Lee Wilson, the boy’s stepfather—he wanted to talk with the boy privately. Officer Brubaker thus became the fourth person to do the right thing.

The officer and the boy walked outside. At first, the boy, who was markedly underweight, said his bruises were from an accident. But another officer with experience in cases of battered and traumatized children— Sgt. Sonja Saunders —soon arrived and patiently continued listening to the boy, becoming the fifth person that night to do the right thing.

From Officer Brubaker’s official report:

“I immediately noticed bruising to the right side of his face and what appeared to be a healing wound on the bridge of his nose . . . Upon further observation, multiple bruises were seen on his right arm starting from his shoulder all the way down to his wrist . . . [The boy] stated Timothy Wilson has recently been beating him with a wooden broom, back scratcher and his closed fists. [The boy] stated he beat him with these when he does something wrong . . . [He] also stated Timothy Wilson would punch him in the chest with closed fists.

“It should be noted that [the boy] was in pain just by simply rolling up his jacket sleeves to show his injury . . . [He] complained of chest pain and was hunched over while on scene . . . It should be noted, [Timothy Wilson] weighs approximately 325 pounds” and the boy weighs “approximately 60 pounds.”

An ambulance was summoned, and the boy was transported to a hospital, where extensive bruising was found beneath his clothes, and on his ears. Timothy Wilson was arrested on the spot. Follow-up interviews with the boy by detectives led them to allege, according to police and court documents, that the stepfather had fastened straps to the child’s ankles and neck and had hung him upside down from a door; that the boy had been beaten with various objects, handcuffed to a moving cart, ordered to do military-style exercises for 30 minutes at a time and, if he failed, punished by further beatings and by not being allowed to eat.

Prosecutors from Florida’s 9th judicial circuit charged the stepfather with 10 felony counts including aggravated abuse, false imprisonment and neglect; his wife, Kristen Swann, was charged with five felony counts of abuse and neglect. Both have pleaded not guilty. The boy and girl, police said, are now safely away from their purported guardians.

If any of the five people that night had decided not to get involved, according to Detective Erin Lawler, “that little boy would probably not be with us much longer.” She called what was done to the child “torture” that “shocks your soul.” Police Chief Orlando Rolón said that were it not for the quick action that night, “We probably would have been talking about a potential homicide investigation.”

But all five instantly knew what they must do. Because they did, Timothy Wilson and Kristen Swann await trial. And that boy is alive.