Based on Series 3, episode 3: His Last Vow.
My version of when John visits Sherlock in the hospital after being shot (because we never saw that) by John's wife, Mary. My version of this happens after Sherlock was revived. Enjoy : )
Hours after Sherlock's surgery to remove the bullet. John sat by Sherlock's bedside. He had his eyes shut as he waited ages for Sherlock to wake up until he heard finally heard groaning coming from the hospital bed. John snapped his eyes open and jumped up.
"Sherlock?" John leaned over his friend, waiting for him to open his eyes. "Sherlock. It's John. Can you hear me?" He smiled when Sherlock opened his eyes slowly. "Oh thank God." John smiled in relief.
"John." Sherlock spoke with a hoarsely voice. He was barely audible but he started to panic. "John...danger...Magnussen." John placed his hands on Sherlock's shoulder and arm.
"Sherlock calm down, it's alright." John comforted Sherlock whilst ignoring Sherlock's words. Sherlock finally calmed down because he knew at the moment that John was safe. John removed his hands and sat back in the chair.
"You had me worried." John spoke. Sherlock looked at John with a confused face. "You died Sherlock, for about ten minutes." John sighed. Sherlock continued to stare at him, scrunching his eyebrows as he took it in.
"Moriarty...Redbeard...put down." Sherlock continued to babble while referring back to his Mind Palace as he fought to keep conscious and alive.
"You must be on a lot of drugs." John smirked then remembered something. He thought it may be the chance to ask Sherlock a very important question as drugs can make people blab out the truth sometimes. "Sherlock, do you know who shot you?" John asked. "Lestrade called me to ask you when you woke up." It was probably the wrong question to ask at the wrong time but he had to ask.
Even though he was on a lot of morphine, Sherlock thought long and hard on what he was going to say but Sherlock didn't answer, he just continued to look a John with a frown. He didn't want to tell John. Not yet. "Okay, you don't have to answer that now." John spoke with a smile. "How you feeling?" He changed the subject.
"Like I've escaped death." Sherlock smirked tiredly as did John but his smile left.
"How could you be so stupid, Sherlock? Going up there without back up!" John frowned.
"You know we couldn't call the police and I didn't realise she had a gun, John." Sherlock closed his eyes, trying to ignore the dizzy spell from his drugs.
"So it's a she. Thought you didn't know who shot you?" John interrogated.
"I heard a voice and it was only me, Magnussen and the shooter." Sherlock quickly covered his tracks.
"Alright." John replied, still quite curious but ignored his feeling as he watched Sherlock close his eyes from tiredness.
John got a text alert from Mary saying "I'm here." He replied to where he would meet her then put his phone back in his pocket.
"Mary?" Sherlock asked as he looked at John's face. John looked up at Sherlock.
"Yes, she's here." John replied. Sherlock slowly sat up a bit as if he was trying to get away, he felt unsafe suddenly. "I'm going to go meet her. I'll let you rest. I'll be back up later." John smiled then left the room.
Sherlock watched as John left his private room. Sherlock threw his head back into the pillows after increasing his morphine intake and then closed his eyes to fall back to sleep.
As John closed Sherlock's door behind him. He suddenly smiled with excitement. The thought of Sherlock being alive made him feel so relieved and the fact he was awake was even better. He saw Mary come along the corridor and met her at the stairs she walked up.
"Mary." John spoke to get her attention.
"Hey." Mary responded.
"He's only bloody woken up." John beamed with excitement.
"Seriously?" Mary smiled with John.
"Yeah. You, Mrs Watson. You're in big trouble." John playfully pointed his finger at Mary.
"Really? Why?" Mary's smile went to a confused look.
"His first word when he woke up?" John queried. Mary shook her head lightly, confused. "Mary!" John answered as he quoted Sherlock. She giggled along with John and hugged him so he couldn't see her guilty face as she frowned.
So that's my theory of the visit. I'm probably really wrong and something like this didn't happen but who knows. Hope you enjoyed it. I'm probably going to work on my own story of Sherlock next since I have a few ideas. See you then : )