He woke up with an uncomfortable feeling in his arm, as though it had fallen asleep. A moment later, that theory was confirmed as he realized he was laying on it. Another moment and he realized he couldn't see.
He panicked for a couple of seconds, suddenly remembering what had happened, as much as he knew - they must have crashed - John! and where had Mycroft been sitting? where had the car been hit? - but he realized the reason he couldn't see was only his hair, matted with blood, was in his eyes. Not that that really calmed him down much, but he could brush it out of his face now and look around to see what had happened.
Next to him in the back seat, John and Charlie were stirring feebly. They looked all right at first glance, so he moved on, sitting up to make sure that he himself was all right.
He had a cut on his forehead from slamming into the hard ridge on the back of the seat in front of him, and his arm was still tingly from where he had been laing sideways on it, but other than that he was all right.
In front of him in the middle seat he could see Cassidy, Rob, and Michael, who was rather pale, but who was also looking around to see if everyone was all right. He said something to Sherlock when he realized he was awake, but Sherlock ignored him, instead looking up to the front two seats where Mycroft and Mrs Johnston had been sitting. He couldn't see Mrs Johnston at all, really, other than the side of her head, which moved as he looked at it, wobbling on her neck as though she was having trouble waking up and controlling it. Mycroft he could see clearly, though.
He was slumped against the right side of the car, seatbelt pulled tight. Sherlock could see blood in his hair, and he wasn't moving, and what if - no, he would stay calm, because John was waking up and he didn't want John to panic either. Which some effort, he took a deep breath, closed his eyes, and relaxed. Relatively.
And now John was all the way awake, and Sherlock could see his eyes widen as he figured out what had happened. He looked around the car for a moment, then turned back to Sherlock, a worried question written on his face.
"What happened?" he asked.
"I... I think we got into a car crash," Sherlock said.
"Are we gonna die?" Charlie whispered suddenly, and Sherlock knew he wasn't taking it well. Charlie's eyes were wide and panicky, his breaths getting shorter and shorter as the blood drained from his face. Sherlock had to keep him from panicking, so he did what he abhorred at any other time - reached across and grabbed Charlie's hand.
"We'll all be okay. No one is going to die," he told him, squeezing the hand nearest to him. Charlie didn't relax, really, but he did calm down a little. He was still pale, and still breathing faster than he probably should have been, but he was calmer, and he wasn't panicking any more.
"Sherlock?" he heard Michael say just then. "How are you doing? Are you guys okay?" Michael was speaking in a weirdly calm voice.
"Yeah, we're okay, I think," Sherlock said. "I have a cut on my forehead that's bleeding a bit, but it's not too bad, I think. And Charlie is freaking out a little bit. But we're mostly okay. Are you..." He trailed off, not wanting to finish his sentence, because to do so would mean thinking of all the possible injuries, all the bad things that might have happened.
"Cassidy sprained her wrist or something, and Rob bit his tongue really badly, poor guy, but we're pretty much okay other than that," he said.
"That's a lie, Michael, I can tell from here that your nose is broken," said Cassidy. Her voice was thin and strained, but clear.
"That's not important," said Michael.
"Yes it is," she said.
"It isn't. Now hush, I'm having a conversation," he told her, and she grinned, seeming to have gained some strength from their disagreeing somehow.
Mrs Johnston spoke up then. "I'm sorry, guys, but can you be kind of quiet? I have the worst headache right now."
"Sorry, mom," chorused a handful of voices.
"Should we call 911?" asked John after a moment.
"Yeah," Michael said. He pulled his phone out of his pocket and dialed.
An ambulance arrived after what felt like forever, but was really just eight minutes. It turned out someone had already called 911, although they hadn't stopped to see if anyone was okay - probably the same person who had hit them. There was a paramedic who helped Mycroft out of the car - it turned out he had a rather bad concussion, although he would be okay eventually.
When John tried to stand up to get out of the car, he screamed and fell back into his seat - a sound that sent a chill all the way down to Sherlock's bones. He didn't think he would ever forget that sound.
John had a badly broken leg. The paramedic didn't tell Sherlock much, but when he was talking to Mrs Johnston Sherlock caught the words 'hospitalized' and 'a few weeks at least.'
He didn't remember much after that.