Not Again (Johnlock AU)

Mystery Man

John and Mary ended up talking for hours. 
John found out Mary had just broken up with someone and was currently single and she worked at a small office around the corner...she didn't tell him what or who she worked for. Mary found out about Sherlock and how attached John was to him.
Weak spot No. 1: Sherlock. 
She found out about the flat and Mrs. Hudson and all the people he knew at St. Barts Hospital.
Weak spot No. 2:  Mrs. Hudson.
Weak spot No. 3: 221B Baker Street.
                                   

                                                                             -  -  -  -

        "This was a lovely evening Dr. Watson. Thanks again for letting me sit at your table." Mary said putting on her coat and beginning to walk out. John nodded and hesitated before grabbing her arm. "Will I ever see you again?" He asked. Mary smiles and pulls out a small sheet of  paper and a pen and begins scribbling down numbers. "Here. Why don't I give you my number and you can call me whenever you like? Then we can see eachother again Dr. Watson." She says handing him the paper. John smiled and nods and puts the paper in his pocket as he opens the cafe door for her. "I should take you home." He mumbled. "Oh, no. That's alright! I had...somewhere else to go anyway...good night." She says quickly walking out of the cafe and into the busy streets of London. 
        

        John watches her leave and walks out of the cafe a few minutes later. He walks a few blocks before stopping in shock.  She called him 'Dr. Watson' he never told her anything about his job. How did she know? 
John continued to ponder of this as he walked by the same alley from before. As he did, he heard trash lids fumble over and hit the ground loudly. Again he stopped and stared into the dark alley. In the corner of the alley he could see the silhouette of a man quickly grabbing the lids, trying to stop the sound. The same figure. The same man who had saved him. John walked into the alley and tried to reach the man. "Excuse me! Sir? I just wanted to thank you for before..." He said approaching the man.

       The figure looked around before climbing a ladder that lead to the rooftop of the building. John ran towards him but his leg picked at him with pain so he limped towards him instead. "Hey! Wait!" He yelled, but the mystery man had already gotten to the roof. He looked down at John and whispered, "I'm sorry...John." Before running away. And as he did John practically fell to the floor in shock. Not because of what he said since he didn't hear him, but because he could have sworn he saw dark curls under the mans hood. Dark curls. His curls. Sherlock's curly dark locks. Him.