Summary: 'Reichenbach Reversal' Fic. What if John was the one to fall and Sherlock was the one left behind to pick up the pieces. Can their marriage survive this or will their love fail them? Johnlock, Mpreg

Disclaimer: All the rights to the characters and music for this fic belong to their respective owners.

A/N: So this is an idea that I wrote out a while ago and just never got around to posting. Hope you enjoy.

Chapter One: IOU a Fall

"Doctor John Watson. The heart and soul of Sherlock Holmes."

John fought not to scowl at Moriarty's casual greeting as he stepped out onto the roof of St. Bart's hospital. The psychopath was facing away from him, watching the people milling in the streets below them with an indiscernible expression. Not for the first time, the former army doctor found himself wondering just what the hell he was doing.

He'd received the text earlier that morning on his way to and since then he'd been on edge, knowing exactly what would happen and dreading it. He could only hope and pray that everything went according to plan. Luckily, Sherlock was working a case for Lestrade and hadn't had a chance to pick up on his unease. Steeling his nerves, he allowed his heart to harden and the hate he felt for the man before him to flood his veins.

"Moriarty." He spat.

The consulting criminal chuckled darkly at the scorn in his voice and turned to him, dark eyes full of malicious amusement.

"Well here we are, Doctor." He purred. "Do you know why you're here? Why Sherlock isn't?"

John snorted, a thin trill of terror rocketing down his spine. "No, but I'm sure you're going to tell me." He sneered, and Moriarty grinned viciously.

"I owe you a fall." He sang softly, repeating the words he'd text the doctor that very morning. "You are here because you are going to help me burn a heart out of Sherlock Holmes. I promised I would and you're the perfect person to help me."

"And if I don't?"

Another chuckled left the criminal, deep and dangerous, an insane smirk curling his lips into a blood-chilling parody of a smile.

"He'll die."

John heart stopped cold in his chest. Of course, he had suspected this outcome however somehow, hearing it spoken out loud just made it all the more terrifying. Sherlock couldn't die. There was still so much good he could do. So many people that still needed him. Their son still needed him!

"N-no." He breathed and Moriarty nodded, voice taking on a sing-song lilt.

"He'll die. Lestrade will die. Mrs. Hudson. Harry. They'll all die unless…"

He hadn't mentioned Hamish, his and Sherlock's three month old son. Good, that meant he was as unaware of the child's existence as everyone else. After all, Moriarty was not someone that would keep an advantage like that to himself. That was good, their son was safe.

"Unless I jump. Finish the game."

"Four snipers. Four bullets. They all die if you don't. Your death is the only thing that will call off the killers."

John swallowed.

"Sherlock will be able to find them. Find you. If I die, he'll keep coming after you until he destroys you."

A bluff, a good one though. Sherlock was unpredictable at the best of times and John honestly had no idea how his death would affect his detective. All he knew was, it would be bad, very bad.

Moriarty bought it, but didn't seem concerned, his smirk widening into a largely disturbing smile.

"No he won't." He sang, pulling a gun from his coat. "You see, the game is over. Without me, Sherlock cannot win." He tilted his head, dark eyes glittering with unsurpassed madness. "And neither can you."

"Y-you're mad." John breathed, horrified and the criminal giggled.

"See you in hell, Johnny-Boy." He replied, before putting the gun in his mouth and pulled the trigger.

The army doctor yelped and jerked away, his hands trembling as he stared at the warm corpse in horror. His phone vibrated in his pocket and he pulled it out numbly, heart plummeting as he read the text displayed on the screen.

"Coming to Bart's to view the body of the latest victim, meet us in the lab. – SH

No! Sherlock wasn't supposed to come here! He couldn't do- he had to or his Sherlock, his heart would die. He had no other choice. Tears filled his eyes and he glanced at Moriarty's prone form before stepping onto the ledge of the roof and dialing Sherlock's number. Down below, he spotted his lanky detective climbing out of a cab with Lestrade. The curly-haired man stopped as his phone rang and John could just imagine the small furrow in his brow when he answered.

"What is it, John?"

"Sher-" His voice broke. "T-turn around, love."

"John, what th-"

"L-look up. I'm on the roof."

Confusion crossed his lover's pale features before he turned and looked up. Their eyes met and the younger man faltered back slightly in shock.

"J-John." He gasped and Lestrade followed his gaze eyes widening.

"I-I can't come down, so I'll have to do this from here."

Sherlock shook his head. "No, John. Get down from there. Get down! You're being an idiot!" He snapped, but the fear John could see in his eyes betrayed the harshness of his words and the doctor let out a broken chuckle.

"I owe you." He continued, as if the consulting detective hadn't spoken. "I owe you so much. After Afghanistan, I was broken, lost. You saved me. You gave me a purpose."

"Then why, John? Why now? Why?"

Sherlock whispered, his voice bordering on pleading. Tears streamed down his cheeks, staining the beautiful porcelain, aand it broke John's heart. In all the time he'd know him, he had never seen Sherlock look so devastated and the fact that it was his fault made it all worse. Damn Moriarty for doing this.

"Because it's too much! The nightmares. The memories! I can't do it anymore, Sherlock! I can't! I'm sorry."

"John, please. What…What about Hamish? What do you expect me to tell him?"

John felt his resolve weaken, but he forced himself to continue.

"Don't tell him how I died. I don't want him to know."

His lover stared up at him, eyes wet and lips trembling. Then he glared, his voice low and full of pain and anger.

"You're a liar, John Watson." He snarled at him. "Before we got married, I told you that caring was not an advantage! You promised to prove me wrong."

A sob ripped itself from John's throat, and he looked away.

"I'm sorry."

"Please, John. Get do-"

"I love you."

Sherlock shook his head frantically.

"John-"

"Goodbye, Sherlock."

Tossing the phone away, John took a deep breath…and stepped off the ledge.

"JOHN!" Sherlock shrieked, rushing forward as his husband hit the ground. Everything blurred around him, his entire focus narrowing in on the bloody corpse laying a few meters away. It all felt so surreal, as he were dreaming and sooner or later he'd wake up, John lying beside him sleeping soundly.

Hands grabbed him, trying to prevent him from getting closer to the body but he shook them off, falling his knees beside his husband's broken body.

"John, wake up! Wake up! Stop this!" He yelled at it, shaking him. He had to wake up! He wasn't dead. He wasn't!

Stronger hands grabbed him, forcing him to release John and he screamed and fought against it all, trying to explain to them that his husband was only sleeping. That he had to get him home to their son.

They couldn't take him away, why didn't they understand?

Black spots appeared in his vison and he frowned, reaching blindly for John's hand.

He found nothing but air.

John was gone…

Lestrade had known as soon as they'd arrived at Bart's that something was wrong, however this was not something he had expected. He watched solemnly as the coroner loaded his best friend's body onto a gurney and wheeled it away, thinking of everything he'd learned and seen throughout the day.

He'd been shocked to learn that John and Sherlock were married and had a kid together, especially given how abrasive the young detective was, and he certainly hadn't known that John was suicidal. It broke his heart to know that thanks to his ignorance he hadn't been able to prevent Sherlock from having to suffer from such a fate.

The DI glanced down at the unconscious man in his arms, noting the drying tear tracks on his face and the slackness of his feature caused by the sedation the paramedics had been forced to administer. He shivered remembering the way the consulting detective had screamed and struggled to get to John's body, begging them to just let him take his husband home. His heart wrenching pleas for john to wake up, so they could go home to their son.

He couldn't help but hope that somehow his young friend would recover from this. Unfortunately, he had a feeling that things would never be the same.

TBC…