"You cannot die! You cannot die!" the father mumbles to the bloodied, mutilated boy who lies unconscious on his lap.

His hands press down on the boy's slashed-open stomach to keep the insides from spilling out. He sobs convulsively.

"Listen to me! You cannot die!" he repeats his morbid mantra. "If for nothing else, to exact justice."

The two are on a rickshaw headed to a hospital in Dhaka. It's not the most effective way to transport a dying child through the cramped, congested streets of the Bangladeshi capital. But it's all that the impoverished father can afford.

Hours earlier, four men had surrounded the 7-year-old boy, bound his hands and feet and cracked open his head with a brick. They held him down and took a switchblade to his throat. They sliced his chest and belly in an upside down cross.

And in a final brutal act, they hacked him sideways, chopping off his penis and his right testicle.

"It's amazing that he lived," a doctor would later say. "I'm really surprised he didn't bleed to death prior to getting to the hospital."

This is the story of a boy who not only survived, but is now the key witness in a trial that has forced Bangladesh to confront the cruel but overlooked practice of forced begging.

It is also the story of strangers, half a world away, who set out to show the boy that good exists in equal measure as evil -- and who set off a chain reaction of kindness to make him whole again.

For his safety, CNN has chosen to withhold the boy's real name.

For his resiliency, we will call him "Okkhoy" -- the Bengali word for "unbreakable."

'Pure evil'

It is now almost two years later. Deep scars still crisscross Okkhoy's frail body.

He is afraid to go out after dark. When sleep finally comes, he wakes up screaming.

"Hush, hush," his father -- whom we are calling "Abed" -- reassures him. "As long as I'm here, the devil cannot get to you again."

The attack took place in late 2010, just a few days before the Muslim festival of Eid.

Three area kids lured Okkhoy out of his home with the promise of a popsicle.

"They kept insisting that I go down this to this one area," Okkhoy recounts. "I kept saying, 'Why?'"

His suspicions aroused, Okkhoy says he set off for home when a group of neighborhood men grabbed him and pulled him into an alley.

"They tied me up and told me they'd force me to beg," he says. "I told them, 'I know each and every one of you. And I'm going to tell my father.'"