This is based on a prompt from weasleygirl928 on tumblr. It is an au where Sherlock has to marry Janine for the case. I do not own Sherlock.

ooo

Sherlock's feet were freezing. They were freezing cold in his expensive shoes and socks. Suddenly, he couldn't breathe. Oh God oh God oh God I'm getting married. I'm getting married to her. He tried to wiggle his toes, but they were almost numb. How did I get myself into this?

"Sherlock. Sherlock!" John waved his hand in front of his best friend's face. "You haven't blinked for at least a minute, mate. It's getting pretty scary."

Sherlock pulled himself out of his thoughts and focused on John. "I can't do it."

They were in the groom's suite with Lestrade, Mycroft, and Sherlock's father, and looks of concern flooded each face.

John clapped his hand on Sherlock's back and reassured him. "Of course you can. You're just a little frightened. It happens to everyone. Even me…Just don't tell Mary that last bit," he finished with a smirk. There were murmurs of agreement from Mr. Holmes and Greg. Mycroft had reluctantly promised to keep his mouth shut about his views on marriage, so there was only silence from him.

"I can't marry her." Sherlock repeated. "I don't love her."

"What are you talking about?" exclaimed Greg. "You've been going on for weeks about how much you love her and how excited you are to be getting married. This is just cold feet. Don't worry about it."

It was true. Sherlock had been extremely vocal about his excitement for the marriage and had hardly spent a moment away from the bride's side in practically a month. He appeared to be very committed to this relationship. However, most of his "joy" had been to remind himself of how important it was that he go through with this. No. You are committed to this relationship. Remember: it's for a case. It's for a case. Just keep repeating that.

Before Sherlock could respond, his father jumped in. "Maybe it's just the wedding night you're afraid of," he said, wiggling his eyebrows. Sherlock groaned. He was not in the mood for another conversation about his lack of experience in bed.

Thankfully, John saved him, saying "No, I don't think that's it."

"Alright," started Mycroft to everyone's surprise, "let's think this through logically. Tell us the things you love about her. Maybe then you will remember why you wanted this marriage so much." John and Lestrade looked pleased so Sherlock tried this, determined to keep his focus on her.

"Okay, I love that she's supportive of all my cases." True. "I love running my fingers through her long brown hair." Good so far. "I love how she makes me laugh." Keep going. "I love the way her lab coat falls around her perfect figure." Nope, too far.

John made a horrific noise of surprise. "You like Molly! Those are all things you love about Molly!"

"That would explain why you always jump at the chance to take a case that leads you to the morgue!" added Lestrade.

"And why you're always at her flat," chimed in Mycroft who was apparently, always watching.

His father stood up from his chair in the corner and said, "You know Sherlock, I almost married the wrong woman before I married your mother." There was silence, since not even Mycroft had heard this story. "Yes, she was beautiful. I thought I was in love, that is until I met your mum. She worked at the flower shop at the time and I was trying to find the specific flowers my fiancee wanted. Our hands touched as I was reaching for an orchid, and I felt like I had become a new man. The next day I broke off the engagement and promptly started going after your mum. Trust me, it's worth breaking a heart if it's the heart of the wrong person."

Mycroft looked suspiciously misty-eyed and Sherlock almost said something about it, but then he remembered that the story was supposed to be advice for him. "You don't understand," he said and then mumbled something that ended with "case."

"Sorry, what about a case?" asked John a bit tensely. He gritted his teeth. "I have to marry Janine. It's for a case."

Lestrade threw up his hands. "You can't base your life around one case!"

"This is about love, Sherlock. We can see you don't love Janine, though you've done a fine job pretending. It's obvious that you love Molly. You have to tell her. For her sake as much as yours," said Mr. Holmes. There was a chorus of agreement, even joined by Mycroft.

"What about the case?" asked Sherlock in a small voice. He was teetering on the edge between bolting to go proclaim his love to the right woman and collapsing in a puddle on the floor. All he needed was one word of encouragement.

"Go!" yelled all four men in unison.

Sherlock scampered down the staircase to the hall and burst in the entrance, hearing the organ start to play as soon as the doors opened.

"No no stop!" he commanded. "There will be no wedding today." Janine's side of the hall made confused noises until they were shushed by Sherlock's voice again. "But there will be a kiss. I hope."

He looked right at Molly who was sitting in the back row, wishing she was anywhere but at Sherlock's wedding to had promised him she would come, but now as he looked at her she forgot why. She even seemed to forget her own name.

"Molly. Molly Hooper."

"Hmmm?" She asked staring into Sherlock's eyes.

He reached down and took her hand. "Would you please come with me for a moment?"

She stood up wordlessly and followed him out the back of the hall. They walked outside and ended up on a park bench behind the church.

"What on earth was all that about?" Molly asked finally.

Everything tumbled out of Sherlock's mouth at once. "I don't love Janine. I never have. I was only marrying her to get closer to her employer. It was all fake. But then I realised that I couldn't marry her when I am so in love with someone else. I love y–"

"This was all fake? How could you do that to her? How could you do that to me? How do you expect me to trust you after that?" She started crying angry tears.

"Because I couldn't go through with it, Molly. I couldn't go through with it because of how much I love you. I have done terrible things in my life and hurt people's feelings beyond forgiveness. But you make me a better man, Molly."

"No."

"No?"

"No. This is just selfish. None of those are reasons to trust you." Molly started to get up and walk away, but Sherlock stopped her with hand around her arm.

"It's only selfish if I'm the only one who wants this." He paused. "The reason I was going to marry Janine was to solve a case and prevent a terrorist threat from becoming anything more than a threat. But then my father reminded me that you deserved to know how I feel. Say the word and I'll walk away, but don't sacrifice something that could be wonderful just because you're mad at me."

"You're going to have a lot of work to do. And you owe your father a pretty big 'thank you'" replied Molly, wiping away her tears and looking at him. Her eyes were still full of hurt, but he could see a small glint of hope.

Sherlock drew her into a hug and stroked her hair. "Thank you Molly."