It was a fairly enjoyable Thursday afternoon. Sherlock and John were sitting on a bench.

"Sherlock?" John murmured on a moderate ton.

"Yupp?"

"Err" he continued disconcertedly. "If one day Mary jumps into bullet... to save you. You won't ler her do it, will you?"

"Sure wouldn't buddy" Sherlock answered calmingly.

"So you save her under any circumstances?"

"Yupp."

"Even if she acts in the heat of the moment and you have like a 0.00003 sec to inhibit?"

"Yes. Of course."

"So if she dies in such circumstances, am I allowed to blame you and end our friendship?"

"Thought you would never ask. That would be a completely logical move, my friend. I'm so proud of you."

"Aww" John blushed. "You're the best, Sherlock."

"No, you're the best."

"So... you swear you'll do that?"

"Yes, I swear."

"Is it a vow?"

"Definitely a vow."

"Thank you. Means so much."

So the two continued sitting on a bench and gazed into the sunset.

A few days later Molly and John met in the store by accident.

"Hi John" Molly greeted him politely.

"Hi Molly" John answered . "What are you doing here? in the shop?"

"I'm shopping" Molly revealed.

"Wow. I'm shopping too."

"Cool."

"So weird we haven't spoken before" John said a bit later.

"I know. However, our personality is quite similar. We're both caring, average people, both working in the medical field I'm assuming..."

"Never thought of that. We should be friends."

"We totally should be!" Molly's eyes kindled. "So I can be like the third godparent of your future child and also, when your wife unpreventably sacrafices herself for your best friend's life, so you'll be widoved and broken up with Sherlock, I can tell him to fuck off and act like your new baby mommy."

"I'm on the board" John nodded. "But there's one thing you've been wrong about. Sherlock would never let Mary to sacrafice herself for him when he can't prevent, he made a vow."

"Ohh. Sorry, I had no idea."

"No probs."

"Wow. Been friends for like two minutes and I already feel reborn."

"Me too, Molly. So happy I had such a productive day."

Meanwhile, Sherlock and Mary shared a productive day together as well in the amusement park.

"This ordinary life is so cool" Mary said .

"Yeah" answered Sherlock.

"Literally I can't wait not to die."

"I know the feeling" the detective sympathized.

"You know what's the best about not dying? You can build a family and have children."

"Good one."

"However, above everything... You're the most important one, Sherlock. You've got the same skills as I do, but you also have curly hair and intense voice, and if you were dead, there were no children left to be orphans. And that makes your life more valuable than mine."

"So nice we spend more time together, Mary. It's so interesting to get to know your thoughts."

"I can tell you the same. You're actually a very nice person, Sherlock Holmes. Can't wait to get myself killed for some ridiculous reason, so I can send you my home-video footage and encourage you to go on with the intense sexual tension you share with my husband."

"I hope I won't find you alive after all, you crafty girl" he winked.

"Lol, that would make so much sense. I just really fucking want to die."

Meanwhile Moriarty was alive but died in a terrible car crash. All of his evil plans died with him. I think this is an important lesson for everyone to be more careful on the roads.