Just to clear things up: TEH happened in November of 2014 and His Last Vow's Christmas was 2015 timeline-wise since the Watsons were married in the Spring.

Molly sighed deeply. It was almost December. Sherlock hadn't even been back for a month, and yet, he was already plaguing her thoughts. She bit her bottom lip as her fingers twisted the engagement ring this way and that as if it would make her feel differently if it hit the light just right. It wasn't long before she had given up the fight. She knew her heart would always belong to Sherlock Holmes—not the famous detective who hid behind the façade of a high functioning sociopath, but the real, flesh and blood man who shared his heart with her.

Speaking of, the detective swept through the doors to the morgue just as Molly switched the radio on. The chorus of Mariah Carey's 'All I Want for Christmas is You' echoed throughout the room, leaving Molly no choice but to laugh at the coincidence. Though she hadn't notice, Sherlock was watching her with an amused look.

"Something funny?" he asked, unable to keep his lopsided smile off his face.

Molly wasn't sure how to answer without giving herself away. "Inside joke…"

He raised his eyebrows in disbelief.

"…with myself," she clarified. Wanting to change the subject, she turned the questioning on him. "How are you adjusting? Being back in London and all."

A surge of affection for his pathologist welled up inside him. "Well, it hasn't been easy," Sherlock confessed. "Change is annoyingly difficult." Including your engagement, he thought. Had he not been an honorable man when it came to loyalty, Sherlock wouldn't have held himself back from snogging her in the stairwell. So, why did he find himself inching closer toward her?

She nodded, empathetic to his struggle. "Look, if you never need an escape from it all, I have a guest room you can use." What was she saying? And, goodness, he was getting awfully close to her. It began to feel warm in the lab…or maybe it was just her face turning every shade of red.

A wistful look reached his eyes, not unlike the one that appeared before the cheek kiss that nearly landed on her lips. Sherlock was taken by surprise when Molly had him wrapped up in a warm embrace. Much to both their surprise, he reciprocated, wrapping his arms around her petite frame. "Thank you, Molly." His voice was soft as velvet.

For the first time since his return, Molly allowed herself this one moment of honesty, coming out in a whisper. "I missed you."

Thomas Barnes may not have been the smartest guy in the world—especially not when Sherlock Holmes was around—but he knew there was something between Molly and the detective. Anyone with eyes could see that. They had been friends for years before he came into the picture, and anybody would be relieved to see that their friend was alive and safe after all. Whatever those two had ran deeper than that, though neither of them seemed to realise it.

As he saw his fiancée hugging the detective, Tom didn't feel jealous or scorned. He felt sorry for them. He knew that Molly loved him, but she wasn't in love with him. No. She was in love with Sherlock Holmes, and possibly completely oblivious to the fact. Tom did love her, but he knew Molly closed parts of herself off to him.

He moved quickly out from behind the glass, going down towards the morgue. Once Tom rounded the corner, he nearly collided with Sherlock Holmes who appeared to be momentarily surprised at his appearance.

"Mister Holmes," Tom laughed lightly. "I'm sorry, I didn't realise you were coming this way."

The detective was noticeably uncomfortable. "Quite alright…Tom?" He cleared his throat. "Well, I must be going. I was just checking on an experiment Molly was helping with."

Sherlock stalked off down the hall, but stopped short before going out the doors. "And one more thing..."—he turned to face Tom—"…Don't let her down. She deserves every happiness."

Tom found it interesting that Sherlock had felt the need to assure him nothing inappropriate had been happening. And nothing was. A hug between friends, though it probably meant more than it appeared on the surface, was nothing to get suspicious about. There was a look in the detective's eyes that he couldn't quite place, but he knew the man must be heartbroken. And then Tom made up his mind. He'd need to keep up appearances until the last possible moment if it was going to work. He was going to help bring them together.

The guilt was eating her alive. She loved Tom, but her heart would always belong to Sherlock. She was irrevocably in love with Sherlock, but his timing sucked. Molly noticed the way he danced around the truth in the stairwell. It damn near killed her to watch him walk away. But it was the right thing…wasn't it? Here were two men who loved her and she was tearing them both apart. With Tom, she knew she was holding back. Deep in her subconscious, she felt like she'd be betraying Sherlock if she opened herself up completely to Tom. At the same time, it wasn't fair to her fiancé; she knew that.

"Hi, Molly," Tom smiled, breaking her out of her reverie. "I saw Sherlock…"

Molly froze.

"…Is everything alright?"

She laughed out of relief. "It's alright. He's just struggling with everything that's changed since he's been…well, gone."

"Remember when you told me you had always wanted to throw a Christmas party at your flat?" Tom asked.

Molly nodded. "Yeah, but we never got around to talking 'bout it. I thought we were going to your parents' for Christmas?"

Tom considered this. "We'll just have the party the weekend before!"

A smile began to bloom across Molly's face. "So…we're actually doing this? I've got to invite John and Mary, and Greg! Anderson would like to come as well, and oh! Mrs. Hudson!"

Tom noted the one exclusion. "Yes, and Sherlock as well!"

Her face fell. "He's not much interested in Christmas parties; trust me, I know from experience."

It made him curious. What happened at that Christmas party from Sherlock and Molly's past? Tom figured the best way to get Molly on board was to present things differently. "Well, we should at least invite him to let him know he's always welcome."

Molly bit her lip anxiously as she thought on it. "You're right; it would be the kind thing to do." Her smile returned. "I need to start planning! I'll see you later!"

She ran off to her office, making the necessary phone calls. Tom was satisfied with how well things appeared to be going. Hopefully, it would all work out.

Author's Note: Surprise! Tom's character isn't being turned into an ass for once lol