At the end of Killing Ground, Hummingbird1759 demanded (;D) a second 'epilogue' to look at what happened next. This is for you Hummingbird, I hope it answers your questions!
The sound of raucous singing assailed their ears as they crossed the pavement, and Mycroft's sure stride faltered. He might even have turned around and retreated, had Ellen not slipped her arm through his, gently urging him forward.
Behind them came John, Sherlock, and Greg, the latter wondering how long it would be before the younger Holmes also tried to turn and run.
Sherlock however, was thoroughly enjoying his brother's discomfort, more so as they walked through the pub door to a loud cheer. Suddenly they were surrounded by slightly soggy ex-soldiers, reeking of beer and all eager to greet John and his friends.
Beckoning Jamie over, John offered his hand.
"It's been a pleasure and a privilege working with you."
"Likewise Captain." The young man grinned back.
Purchasing a round of drinks, Mycroft pulled John to one side, looking puzzled.
"Why are they wet?"
"You remember me saying about survivor's high spirits?" he waited for Mycroft's nod before continuing "just don't let them persuade you to join a game of Dam Busters."
Sherlock sipped his drink, watching john interact with his army buddies, smirking at his brother, surrounded as he was by rowdy soldiers.
Hours later, Sherlock grinned maliciously at his brother "Will you be adding this to your list of places to entertain important foreign dignitaries? Whitechapel's Black Bull"
A/N: John's words to both Jamie and Mycroft reference chapters 11 and 8 (respectively) of Killing Ground)
Dam Buster's is a game once much beloved in the Sealed Knot beer tents, where the 'players' become various parts of an aircraft, they move in unison as the 'caller' banks them left or right, dips or climbs to higher altitude, and when 'fire' breaks out in part of the craft throws a pint of beer over the person playing that part. Messy but fun (and best played drunk!)