A/N: WARNING Series 4 spoilers ahead! This is a Sherlolly one-shot that takes place after the 'I love you' event in The Final Problem. Can Molly forgive Sherlock when he tells her the truth and will she participate in a little experiment on the meaning of love?

Weeks after the gut-wrenching 'I love you' phone call, Sherlock and Molly observed radio silence; neither one brave enough to broach the subject, so they neither spoke nor texted each other. Molly fervently wished she had just said it from the start rather than make him say it first. Because Sherlock said it like he meant it—twice. She knew intellectually that it wasn't true, but his words kept haunting her waking thoughts and even stole into her dreams.

She had heard about the explosion at 221B Baker Street from Mrs. Hudson, so Molly wasn't altogether surprised when John invited her to a housewarming party once the repairs were completed. She bought them an African violet that she hoped wouldn't die from Sherlock's neglect. I'll just ask Mrs. Hudson to water it once in a while.

Sherlock would be there of course, but she had decided it was best to try to put the incident behind her and refuse to talk about it; pretend like it never happened. Molly reluctantly drove to Baker Street and with her plant in tow, she plastered a half-fake smile on her face and knocked on the door. Thankfully it was Mrs. Hudson. "Molly, dear, how are you?" she asked as she gave Molly a hug.

"You know, the same as always," she said with a shrug.

"Well I'm just fixing some tea and biscuits. The boys have wine, if you prefer. You run on upstairs and I'll be up directly."

"Do you need any help?" Molly asked with some desperation.

Mrs. Hudson shook her head. "No dear, now go and have a good time."

If only she knew. Molly sighed and ascended the stairs slowly. When she entered 221B, the first face she saw was that of little Rosie. She didn't have to fake a smile. She placed the African violet on a table, and with a brief hello to John, Molly went right to the child and picked her up. Rosie was happily drooling on her rattle. John looked on as the proud father. Also in the room was Greg LeStrade, whom she greeted warmly.

But where was Sherlock? Molly almost asked but thought better of it. Moments later Sherlock emerged from his bedroom with a piece of paper in his hand. "I knew I still had it and it didn't blow up!"

Lestrade snatched it from him and read it, quickly becoming more irritated by the second. "Did you ever think that perhaps Scotland Yard could have used this? You know I hate it when you withhold evidence."

"What are you complaining about," Sherlock replied defensively, "You got a signed confession. He's doing life. Win-win."

John stood up. "Calm down this is supposed to be a party."

Greg waved his hand, quite willing to overlook it—again. He emptied his wine glass and filled it up again.

Mrs. Hudson entered just then with refreshments, that's when Sherlock turned his gaze to Molly. He started out smiling, then looked discomfited when she didn't return it. She looked away awkwardly and returned her full attention to the infant in her arms.

Sherlock gingerly came up behind her and whispered. "We need to talk."

Without turning around to look at him she replied, "There's nothing to talk about. We'll just go on as always," she said with a harshness Sherlock was unaccustomed to. "I'll be around anytime you need a corpse to beat with a whip or a drugs test."

Sherlock felt a twinge in his heart, though he couldn't rightly identify the emotion that went with it. He used to think he had no emotions at all until John convinced him otherwise. "At least allow me to explain myself."

She shook her head. "Not here, not now."

This had been as much of a torture for him as Molly and he was determined to say his piece whether she wanted to listen or not. He took Rosie from Molly's arms and gave her back to John, who gave Sherlock a knowing look. Then he took Molly gently by the arm and led her to his bedroom. She put up some token resistance but let him lead her. His bedroom was cluttered with piles of books and papers. He swept the clutter off his duvet and offered Molly a seat.

She sat with her arms crossed and looked up at him coldly. "All right, explain."

Sherlock placed his hands together under his chin, looking upward as he considered his words carefully. "I have a sister who I had no memory of until very recently. It was Mycroft who arranged the family reunion. Her name is Eurus Holmes. She's been kept locked away in a prison because she's a psychopathic murderer with a brilliant mind." He didn't tell her she escaped and wreaked havoc in and around London, not wanting to alarm Molly. "I went to the prison to see her with John and Mycroft."

Molly's posture became more open. She appeared surprised by the revelation and motioned Sherlock to continue.

"Eurus ran the place as her own sick little playground and led us through a series of tortures." He paused and took a deep breath. "The worst was a room filled only with a coffin with a plaque that said 'I love you.' I deduced that it was meant for you." He ran his fingers through his curls and started to pace. "She made me ring you and told me that if I didn't get you say those three words she'd blow up your flat."

Molly's eyes went wide. "How could she do that from prison?"

"She has a fantastic network of underlings thanks to Jim Moriarty," he said with grudging admiration. "so I had to assume she was serious, hence the strange phone call. I was forbidden to tell you anything. When the call was over she told me there were never any explosives to begin with. She did it to humiliate both of us. I was so angry I lost it, reducing the coffin to kindling."

"Sherlock," Molly started, "I am so sorry. I hope what I said won't ruin our friendship. I wish I hadn't made you say it first. I can't get it out of my head."

"Funny you should say that," he said. "I'm becoming aware of all these feelings I never guessed I'd ever have, thanks to John's influence. When I said it to you, especially the second time, I felt something in my chest—but I don't know what it means."

Instead of looking happy about it, Molly furrowed her brow and sighed. "You were probably just worried about me."

"No, well yes, I was worried, but I think it was something else, as well." Sherlock cocked his head to one side and asked, "What does love feel like? I've watched Mary and John, and I knew they were in love, but I received no great insights."

"I think it's a little different for everyone," Molly told him. "Romantic love, being with the one your meant to be with is wonderful, or so I'm told. Unrequited love, on the other hand, tears your soul apart. That's why I was so hurt when you rang me."

"John has pointed out more than once that I'm different around you," Sherlock admitted. "You recall that Christmas when I –"

"Acted like an ass?" she gave him a little half smile. "Yes I remember."

"I was truly ashamed of my behavior." He still sounded surprised by it. "I think it was the first time I had spontaneously apologized to anyone. John said it was a Christmas miracle. You've grown into one of my closest friends, but has it turned to love?"

"Oh Sherlock please don't—"

He sat down next to her. "Is there some kind of test to see if it's real or not?"

The earnestness of the question brought tears to Molly's eyes.

Molly sighed again. "A kiss", she said barely above a whisper. "It's not foolproof, but it's the only test I know of. If you feel something like you never want the kiss to end, that's love—probably." She shrugged. "Could also be just hormones."

"We're not teenagers. Let's do an experiment." Sherlock took her by the hands and helped her to her feet. Molly pleaded with her eyes to end this now before her heart was broken once again. Stroking her cheek, Sherlock pleaded. "Please Molly, help me understand."

She nodded and gazed up at him expectantly. Her took her face in his hands and placed a soft kiss on her lips. She let out a little moan that made Sherlock bolder. He teased her mouth open with his tongue, then felt a surge of electricity run from his stomach to destinations south. It was exceedingly pleasant, much more so than when he snogged the bridesmaid Janine Hawkins. He wrapped his arms around Molly and pulled her close. In turn Molly started running her hand through his hair, then put her other hand on his heart. That's when he felt it – his heart skipped a beat. Was that the sign? Sherlock placed his hand over hers and decided that he wanted it to stop at some point (after all, there were cases to solve. He would never give up the Game) though he wouldn't mind if it went on for the rest of the afternoon. After several minutes they finally parted.

"Now Sherlock," Molly said quickly, "you can tell me the truth, but please make it kind."

He grinned. "I felt something—sort of like a little heart attack. It wasn't unpleasant."

Molly smiled tentatively. "What have you deduced from the experience?"

"Inconclusive," he said. "I need to do more research."

There was a knock on the door. "Are you two alright?" It was John.

"We'll be out in minute," Sherlock told him, then he turned to Molly. "I don't know whether I love you or not, but I do know I never want to lose you. It would tear my soul apart, assuming I even have one."

Molly touched his cheek. "That's good enough for now. Come on, let's get out there, I need a drink."

Sherlock smiled, kissing her on the forehead, then walked with her to the sitting room surrounded by friends and family. Instinctively Sherlock recognized that there was already love here—lots of it, and Molly Hooper was a big part of it.

The End