The hardest part

Overview: Each chapter will be based on a different MCR song, it's going to get seriously depressing and slightly AUish. Just so you know.

Summary: Sherlock came back but a lot can change in three years. Cancer fic. Sorry guys.
Rating: M
Disclaimer: Not mine, based on song 'Cancer' by My Chemical Romance

It just ain't living,
And I just hope you know,
That if you say 'Goodbye' today,
I'd ask you to be true,
'Cos the hardest part of this,
Is leaving you.

This was not how Sherlock had planned his return, it was not even remotely close. The 221b seemed to have stooped since he was last there, as though it couldn't take the weight any longer. That alone should have been a sign. The detective entered, the lock had never been changed. Mrs Hudson toddled over and gasped.
"Sherlock?" She squeaked. The tall male had the sense to look abashed.
"Yes, Mrs Hudson." He answered, waiting for her to admonish him but it never came. Something was desperately wrong.
"I think you should go and see him." The landlady pressed, her eyes wandering up to the door which lead up into the flat.

The stairs creaked from lack of use. Sherlock frowned, John was a soldier, he wouldn't let himself fall to disarray. The detective took the rest of the steps in long strides and opened the door, a chilling sense of dread washing over him.

A smell of disinfectant assaulted his nostrils as Sherlock passed through the threshold. The flat had been kept immaculately clean, the door to his bedroom was open whereas the door which lead up to John's looked as though it hadn't been used for years. Holding back the shiver, he crept to his old room.

The smell had gotten stronger, murky light flickered from a light which no one had bothered to change. A figure lay in the bed, deathly pale and barely moving. Sherlock tiptoed closer, the figure was John, that was certain, but he didn't look like John, his skin sagged around his face, he had lost weight. His chest moved ever so slightly but other than that, he gave all pretences of being… Sherlock cleared his throat. Tired eyes cracked open, dully regarding the visitor.
"How did you get in here?" A crackling voice asked, barely above a whisper. Sherlock gulped.
"I'm sorry John, I had to leave. I'm so sorry you had to see me fake my death but you had to believe it was real-"He began. The slight movement of a hand cut him off.
"I knew you were alive. I knew from the beginning. Molly couldn't keep the secret from me when I cornered her with facts. Even you leave a trail, Sherlock." He sucked in a breath. "I asked how you managed to get in here, Mycroft was supposed to keep you away until-" The soldier was struggling to talk now but he fought to get his words out all the same. "-Until I had passed. He was going to tell you I had gone to America."

Sherlock froze.
"What are you talking about, John?" He asked, not wanting to know the answer. The doctor tried for a smile.
"It would be better, you could go on thinking I was alive. He agreed that it would be better." John kept saying 'better'. He was going to get better, right? Something in Sherlock's expression gave him away. "Cancer, Sherlock, it's cancer."

The detective kicked into overdrive, there were many kinds of cancer, so many kinds. They could get treatment, remove any tumours, chemo. They could do anything, something. His shoulders sagged as his rational mind took over again. He knew, he could tell by the way John looked now, it was far too late.
"How long?" He asked, surrendering.
"A week, maybe less." John tried another smile. "You can leave, you know. Just delete it. I'm in America." The detective frowned. John was dying, why was he doing this? Then it struck him like a bolt of lightning. John was protecting him, still, after all this time. He's giving him a lie, a suitable lie, that he can believe instead.
"I'll stay." He replied. "I never should have left."

'Cos the hardest part of this
Is leaving you.