[WP] The saying "Cross my heart and hope to die" comes alive. Anyone who breaks a promise after saying that, dies. Anyone who broke a promise made on that statement before this happened, dies aswell.

"We need to find this sick bastard!" Romero screamed.

He slammed his fist on the hood of the squad car, adding yet another dent. This was the twentieth kid in a month. The killer was careful and calculating, not leaving a single clue. Whatever method was being used to kill these kids was also a mystery. Not a single injury had been discovered.

"Let’s go over it again, Bob," he said, calming a little.

"Come on, partner," Bob said, "go home, get some rest. Let the next shift do some work."

The two cops stared at each other. In fourteen years, they'd never so much as argued. Now, Romero was furious. Any man who could pass this off to someone else was a man he didn't want to know.

"Don't look at me like that," Bod said. "We've been at it over twenty-fours. We need rest."

Dammit, he had a point. Romero wasn’t doing anyone any favors by pushing, but he had kids and was terrified. He'd question one more kid, then call it a night.

"Sorry, Bob, I'm on edge, ya know."

"I feel ya man," Bob said. "I know you're not going to leave it, so we'll do one more."

The man was uncanny. He always seemed to know what Romero was thinking. Calling a little girl to them, they got down on their knees. It always helped to get down the the kid's level.

"I heard cops shoot people," the girl blurted.

"We try really hard not to," Romero said.

She tugged on Bob's sleeve. "Have you ever shot anyone?"

"Nope," Bob replied.

"It’s okay, you can tell me, I'm almost ten."

Bob looked at Romero and winked. "Cross my heart and hope to die."

His body convulsed, his eyes rolled, and he fell over. Romero pushed the girl away, scanned the area, then put his head on Bob's chest. He wasn't breathing.

"Bravo-two-three, officer down. 2706 Harding, roll rescue."

He started CPR on his partner. The little girl cried as she crawled away.

"I didn't do nothing, mister," she whimpered. "Cross my heart-"

Romero whipped his head around. "Don't finish that sentence!"

All the tumblers fell into place. Nearly every kid interviewed told the same story. Of course, nobody connected that silly saying to the crimes. How could they? Romero wasn't even sure himself, but he wasn't about to take unnecessary chances.

"You did it, partner," he cried to his dead friend. "You figured it out."

Tears rolling down his checks, he called it in. No one would believe him right away, but some fool would test his theory, killing themselves in the process. Hopefully no more kids would have to die.

"Goodbye old friend, and thanks."