This happens right after Sherlock tells Greg to look after Mycroft. Possibly some Johnlock in here. Hopefully you like it. Sorry for the shit description. It's a rp with 221B-Baker-Street. Sorry if it's not book standard.
Mycroft had always warned Sherlock that feelings can get in the way, especially when it comes to his chosen line of work. Typically, this would be the one thing the two brothers could agree on, however, when you reappear on his doorstep after years of no contact, informing Sherlock that your life's in danger, he's left struggling with both his feelings and what happened in your shared past. How can he possibly pretend such strong emotions have never existed when they still remain?