Molly slowly pushed the trolley through Tesco, trying to decide what she wanted for dinner. It was a challenge cooking for one. Most days, she simply ate in Bart's canteen but she was off today and there was nothing in her fridge. She surveyed the options then decided on something simple she couldn't mess up like pasta. It was in the next aisle so she absently turned about and immediately crashed into ...

"Sorry!" she exclaimed, watching Sherlock wince as he stepped back from the trolley. She's hit him somewhere on the upper thighs and feared somewhere else as well. "I'm so sorry, I didn't know you were ..."

"I'm fine," he snapped, his eyes darting about to the other shoppers staring at them. He grabbed the end of the trolley and pulled it and Molly into an empty aisle. "I need you for about an hour. Maybe two."

"At Bart's?"

"No, I have to look at a flat and I need a ... " Sherlock paused, his face twisting up again before continuing. "Girlfriend."

"A what?" she asked, not sure she heard him right. He gave her a strange look and Molly took the opportunity to ask something else she'd been dying to know. "I mean, surely you have one."

"No," he said firmly as if the idea was preposterous. Molly's expression fell as a sudden thought struck her. Sherlock's eyes narrowed as he watched her reaction, then held up a gloved hand. "And before you ask ... no, I don't have a boyfriend either. Doesn't matter - I just need you to come with me."

"What ... now?" Molly asked, stepping around the trolley. She gazed down at her clothes and wondered if they were appropriate. Thankfully, her long coat covered everything except her jeans and trainers.

"Yes now and what you're wearing is fine," he said, taking her by the arm and leading her out of the store quickly. He let her go long enough to wave down a taxi. "I have an appointment with the property agent in 20 minutes. I need to get something out of the floorboards in the back bedroom and someone has to distract the agent. Can you do that?"

Molly nodded just as a taxi pulled up. Sherlock held the door open and waved her in. She stood there for a moment, then eagerly climbed inside.

She was about to go undercover with Sherlock Holmes.

The property agent was waiting out front when they pulled up to the posh building. Sherlock jumped out first, then offered his hand to Molly. He pulled her out, shut the door and reached for her hand again. This time, he laced his long fingers with hers and Molly wished he didn't have gloves on.

"Sorry, we're a little late," he said to the agent, smiling cheerfully. "Darling, this is Mary Campbell. Mary, this is my fiancee, Caroline Ellis."

Molly's eyes widened slightly at the word "fiancee" but decided to play along.

"Pleased to meet you," Molly said, nodding politely at her. Mary looked up and down Molly in silent appraisal as if she was trying to figure out how they could possibly be a couple.

"Shall we see it?" Mary said, entering the pass code for the building. She held the door open and ushered them inside.

The lobby was even more posh and elaborate. Molly felt instantly out of place but Sherlock seemed to fit in perfectly. He strode confidently beside her, his head held high as they followed Mary into the lift. "I'm showing this flat again at four o'clock. If you're interested in the slightest bit, I need to know immediately."

"It's why I wanted Caroline to see it with me," Sherlock said, his hand releasing hers so he could wrap his arm around her shoulders instead. Molly reeled as he drew her against his chest and placed a kiss on the top of her head. "It's up to her, really. Anything you want, darling. Anything at all."

Mary smiled at that and at them. Molly closed her eyes, enjoying the feeling of being in his arms even if it was all pretend. She wound her arms around his waist, holding him closer. She tucked her nose against his coat and breathed in. He smelled of wool and men's soap and she loved the combination.

The lift stopped on the eighth floor and Sherlock loosened his grip on Molly. He let Mary walk on ahead down the hallway, making sure there was enough distance between them before leaning in.

"I need about three minutes. Chat her up in the kitchen," he whispered in her ear. "Tell her we're expecting."

"Expecting?" Molly whispered back. Before she wrap her head about that one, Mary had the door to the flat open.

"It's 1,279 square feet," she started, gesturing for them to enter. Sherlock released Molly, then breezed on ahead into the flat. Molly walked slower and gave Mary her full attention. "Two bedrooms, comfort cooling, underground parking and a 24 hour concierge."

"May I see the kitchen?" Molly asked politely.

"Certainly. It's right over here," Mary said, holding her arm out. "It's a bit small but as you can see, it's been completely refurbished. Do you like to cook, Caroline?"

"Not really," Molly answered, seeing Sherlock dart into the back bedroom. She tried to think of what to say next to keep this woman occupied. When she couldn't think of anything, she decided to just say it. "Actually, we're ... expecting."

"You are?" Mary said, her voice rising in pitch. "Oh, that's lovely! Did you just find out? You certainly aren't showing."

"Found out today, actually," Molly said, continuing the lie. She pressed a hand to her lower abdomen. "It was quite a surprise. Haven't really told anyone yet. Except you. Not sure why I told you. I guess I can't believe it myself."

"Well, it certainly changes your housing needs," she said, her eyes lowering to Molly's hand. She reached into her coat and pulled out her iPhone. "I've got some other listings you might be interested in. Somewhere with a bit of a yard, perhaps? I know of just the one."

"Yes, that might be better," Molly said, smiling nervously as she tapped and swiped at the screen. Molly took advantage of the distraction to glance over at the bedroom. No sign of Sherlock.

"Ah, here it is," Mary said, handing her the iPhone so she could look at the photos. "It's also got three bedrooms - in case you end up with twins. Do they run in your family?"

"Thankfully, no," Molly replied, swiping through them as slowly as she could. When she finally ran out of photos, she handed the phone back. "Would it be possible to see it? In person? Perhaps tomorrow?"

"See what tomorrow?"

Molly breathed a sigh of relief as Sherlock reappeared.

"Another listing," Molly said, hoping it was the right thing to say. "I'm sorry, I told her about the baby and this ..."

"This flat obviously won't do now," Sherlock finished for her, wrapping his arm around her again. "I'm very sorry, Mary but I've just received a text from the office and I must get back. You understand, don't you?"

There was a moment of awkward silence and Molly felt her face flush.

"Yes, of course," Mary finally answered, but it was obvious she was annoyed with him. She turned her attention back to Molly. "Caroline, what time are you available tomorrow?"

She felt Sherlock's fingers press into her shoulder insistently.

"I'll have to check my schedule," Molly lied, giving her an apologetic look. "Can I call you later?"

"Certainly," she answered, her gaze moving from Molly to Sherlock. "You have my number."

"Come along, Caroline," he said, nudging her impatiently. "I really must get back."

"Okay," Molly said timidly as he led her out of the flat. He kept his arm around her all the way to the lift. It wasn't until the doors shut that he let her go. Sherlock stepped to the other side, putting some space between them. "Did you get what you wanted?"

"Yes," he answered, reaching into his pocket. He pulled out his mobile and began texting. For a moment, Molly thought he had forgotten all about her but then he looked up. "I must see Lestrade immediately. Can Tesco wait a bit?"

"Yes," she answered, smiling back at him. It could wait forever as far as she was concerned.

Molly was put in a waiting room while Sherlock spoke to Lestrade. Apparently, the floorboards had contained some sort of documents that would clear a suspect's name. She could see Sherlock through the glass partitions as he paced about. She was so distracted that she almost didn't see Sergeant Sally Donovan enter the room.

"I was told to bring you some coffee," she said, not bothering to hide the irritation in her voice. Molly immediately turned her head but it was obvious what she'd been doing. "This doesn't change anything, you know."

"Change what?" Molly asked, unsure of what Donovan was getting at. Surely her feelings for Sherlock weren't that obvious, were they?

"He works alone," she said, handing Molly the coffee. "Sociopaths don't have friends or relationships of any sort for that matter. He's just using you, like he uses all of us. This case? We didn't ask for his help. He just took it upon himself because Freak was bored."

"He's not using me," Molly said, but she didn't sound convincing. She tried again. "He just needed someone to help ..."

"He needed someone to lie for him," Donovan said, giving her a harsh look. "He doesn't care what it takes to solve a case. One way or the other, he was getting into that flat today. Taking you along was just easier."

Molly opened her mouth to say something, but nothing came out. Donovan had a way of making her feel more of a mouse than Sherlock did. She took a sip of the coffee instead and let the woman continue.

"Just stay away from him," she said, then turned to go. Her path was blocked by Sherlock, who was pushing the door open. They glared at each other in a silent standoff that ended when Donovan stepped back.

"Interesting advice coming from you," he said, then turned his attention to Molly. "I must accompany Lestrade to make the arrest but I've been told Sergeant Donovan can give you a lift back to ..."

"Thank you," Molly said, cutting him off before he could say Tesco. Donovan's eyes narrowed as she clenched her jaw in anger. "I'll see you at Bart's."

Sherlock nodded once in agreement, then left. Donovan stared at the door for a moment before turning to Molly.

"I have to make a couple calls and then we can go. Just wait here," she said, slamming the door behind her.

Molly watched her disappear into a back office. She wondered what Sherlock had done to make Donovan hate him so much but then decided it was best she didn't know.

She closed her eyes and thought instead about the feel of his arm around her, the smell of his coat and how much she enjoyed working this case with him. Obviously, he didn't work entirely alone. Even if it was just to lie for him, he still asked her to do it.

Molly opened her eyes as she realized something.

Maybe he needed a partner ... someone to work with.

Maybe she could be that someone.