(Sherlock's POV)
Sherlock sat down at the couch, folding his hands. Not a single word being said, though his facial expressions easily showed his concern for his young son. His eyes wandered around the small apartment in search of clues that Hamish might had left behind. For all he knew, he might have been threatened long enough to leave behind something, a note, just something out of the ordinary. He had to give up, as he couldn't see anything that looked like a clue or cry for help, but then again he knew how stubborn Hamish could be and how he probably would have wanted to find solutions to his own problems no matter how big and dangerous they were; quite similar to Sherlock himself.
His hands were shaking slightly. He cared more about Hamish than words could express, but still he let this happen to him. He blamed none other than himself for not being able to prevent this from happening.
"Sherlock?"A voice called out. It was John. His voice sounded worried.
"Moriarty called," Sherlock mumbled with a low voice, slightly unsure of how to tell John the news.
John frowned. Confused, as he knew how things usually became ten times more serious as soon as Moriarty were implicated in the crime and why would he call Sherlock? Something was definitely wrong.
"What's happened?" He asked after a few seconds of unpleasant silence that felt significantly longer than it was.
Their eyes met as they exchanged a worried look. No matter how hard it was, he had to know. There was no way out of the situation.
"John, he's got Hamish."
The look in John's eyes that moment could be described as both panic and anger. As Sherlock had guessed, he was more or less in shock.
"I believe we have to clean up in this ourselves", Sherlock said quietly. John didn't even hesitate before following him as he tried to control the sudden anger and panic he felt.