So, here's the last fourth chapter thanks to very patient ElementaryFan again... Hope you'll like it and thanks to all of your reviews!

(A week later)

Sherlock was standing in the middle of the brownstone's study with a slightly curved back and hands, his fingers dancing on his hips. He was wearing a light shirt, a black vest and dark pants. Instead of wearing traditional oxford shoes, he was barefoot.

He was watching his new companion with concentrated gaze and his eyes gleamed with and an unusually high interest.

He slightly inclined his head and frowned.

When Sherlock was alone in the brownstone, the silence of the old house always seemed a bit oppressive to him.

That's why he had acquired his new friend.

Sherlock reached out and touched the cold tin.

The corners of his mouth created a fine and rare smile but it disappeared from his face immediately. He pursed his lips disapprovingly and grinned.

It won't be quite it, even if he talks.

As he turned away, he heard a key in the lock of the main door. Something inside him leaped with joy.

"Sherlock?" she called him.

"I'm here," he said. It had been barely an hour when Watson had called and requested to meet him. Then he had asked Kitty if she could have given them a little bit of privacy. She had just rolled her eyes and gone out.

Watson appeared in the doorway of the study.

When Sherlock looked at her, he knew something was different.

She had pinned her hair into a charming bun. Apparently, she had left her winter coat to the foyer. She was standing in front of him in a red dress, a white cardigan, traditional black leggings and boots. There was a new distinct pair of earrings dangling in her ears, and her precise and yet relaxed makeup gave her face a slightly different look than usually.

Something is definitely different.

Sherlock took a breath to tell her his thoughts but she interrupted him by pointing at his new friend.

"A new toy?" she asked.

It took him a second to realize what she was asking. Then he smiled.

"Not really. Do you know where the word 'robot' comes from, Watson?"

"No, but you'll certainly tell me."

He looked at his metallic friend agan. It was just a bit smaller than him and it looked a little ... funny. Its face had a bit eerie poker face and the forehead had strange pointy helmet. The eyes, the nose and the mouth looked scary. The hands in gloves and the legs were completely tinny, consisting of several larger pieces. The robot had also a belt and something like a collar which Sherlock cetainly liked immensely. Its chest had a big sign which said "RUR".

"The word 'robot' was used in a novel called 'RUR' for the first time in 1921. The name is an abbreviation for Rossum's Universal Robots," Sherlock said pointing at the inscription on the robot's chest. "The novel was written by the Czech writer Karel Čapek. And this particular word was advised to him by his brother, Josef, who was a painter. It's derived from the Czech word "robota", which means corvée or a labor."

Watson sighed.

"Well... And you have this... machine here because...?"

"He is a replica of one of the first humanoid robots. He was designed by Captain William Richards for the annual exhibition of the Model Engineers Society in London in 1928. He should move and talk if I repair him."

Sherlock turned to Watson.

"His name is Eric," he smiled.

"Nice," she said. "But why is it here?"

Sherlock shrugged.

"I like Kitty and her company but I got recently the impression that some people," he shot his eyes to her, "are hard to trust. So... I got a new more reliable friend," he said, rocking on his heels and both hands tellingly pointed at Eric.

"How adult," she said hiding the embarrassment of his allusions to their last unpleasant encounter.

"I came to..."

Sherlock lightly sighed, thinking to know what was to come. He turned to face her, determined to resolve the situation quickly.

"Watson, I think you've already apologized during your last visit. I thought a lot then ..."

"Really?"

"Despite my little experiment with Eric here, I have lately understood your concerns for my sobriety. I admit that your behaviour surprised me. And maybe it will take a while before I can fully trust you again. But in the past, you never did anything what suggested that I should not trust you. Rather the opposite."

She took a breath and something inside her hurt.

"Sherlock, please, listen to me."

"Watson, I'd really like to close this problem. If you want, we can have tea or devote a little more to the history of robots together, if you're interested?" he said with great fervour in his voice and with such an innocent childlike enthusiasm that it almost brought tears to her eyes.

"I have to tell you something," she said quickly with a serious face before he could interrupt her again. When Sherlock looked in her eyes, his nagging feeling of something being not right returned. Her demeanor made him nervous.

"I'm leaving," Watson said finally. "I'm moving from New York," she announced. With those words his worst nightmare had come true. He stared at her and tried to find the slightest hint of a bad joke in those dark eyes. But vainly.

"I beg your pardon?" he managed to say, his voice sounding choked and strange.

Embarrassed, he looked away and coughed slightly.

"I came here not to apologize but for a farewell. You were right, last time, about everything. I'm not your sober companion and I have no right to interfere your life. I know I harmed you last time but the way my words hurt you assured me that your sobriety is stronger than we think. You don't need me anymore."

"Watson..." His dancing fingers clenched into fists. Suddenly he felt an unbelievable emotional pain. So strong, it almost paralyzed him.

"I'd like to continue my work," she said. "But elsewhere, where I'll be just as useful as I'm here. I'm so grateful for all the things you taught me but I don't want to live with a constant worry about how you feel. We're friends, yes. But I still don't want to return back to the beginning of our relationship. You will not be alone, you have Kitty here, and Alfredo, Marcus, even Captain Gregson. I need a life on my own..."

Watson's words stuck in her throat at the sight of Sherlock's wounded blue-gray eyes that seemed to be still hoping she was just kidding.

She sighed and came closer to him, as close as a friend can afford. She reached out and touched his elbow lightly.

"I'm sorry," she said.

They stood quietly in the room, her fingers still on Sherlock's arm, and neither of them knew what to say or to do.

"You're leaving," he said a bit absurdly, as if he needed to hear those words again, aloud, to really believe it.

She nodded.

He took a step forward her personal space, hesitantly and so reluctantly that Watson suddenly saw him as a shy boy who speaks intimately with the girl for the first time.

Her hand left his arm.

"You have a responsibility to the one who you bind," he whispered.

She frowned slightly and looked up.

"Paraphrase of The Little Prince," Sherlock explained the quote with a slight smile Watson knew she would never forget.

"I can feel it, I... know I want you to be happy... But I don't want to lose a friend who you are to me, Watson."

She shook her head and stepped away from him.

"Do you know what is really strange?" she asked suddenly.

"I have no idea."

"You call me a friend all the time but you have never ever called me by my first name."

He looked surprised.

"I never thought you care about such a detail."

"A detail?" She smiled sadly.

"Watson..." Sherlock threw up his hands helplessly.

"I should go. You have my number and you can call me ... if you need some consultation." She was about to turn around and leave, but then she heard the last thing she would have expected at that moment.

"Joan," Sherlock said hesitantly.

She stopped immediately.

God... Is it possible that my own name sounds as seductive as said it wih his voice?

Watson looked at him and got the feeling he might explode at any moment. She remembered their gathering here, long ago, after her abduction. He ran to her and didn't know if to embrace her or what, just like now.

But this time, Sherlock surprised her.

He raised his hand and placed it gently on her shoulder.

"Joan," he said again, and it seemed as if he was cuddling with that single word.

And then, suddenly, he hugged her.

It was like... like her core would have fallen apart. Joan felt immediate weakness and dizziness from his grasp and scent. She felt his height, body, muscles, tension, all in one second, while he breathed the sweet scent of her hair. They were standing in their strong embrace and fighting with the desire to never end it.

"Sherlock..." Joan whispered. He got scared that he might had held her too tightly. He released her, but didn't step away. He looked into her eyes and a memory of her words to Sherlock passed her mind.

I'm gonna miss this. I think what you do is amazing.

Under the weight of having exactly the same painful feeling again, Joan felt an abrupt compulsion to do something. Anything. She reached her hands towards him and touched his firmly switched shirt collar.

She heard his breathing in the silence of the room.

She undid his last button.

"I've always wanted... I've wanted... this..."

Sherlock stopped her with an excited voice.

"I told you once that you're far more interesting person than you give yourself credit for."

After that, he hesitantly reached his slightly trembling hand on her cheek.

Joan closed her eyes, and when he saw her expression, he felt so strong feelings and the insane fear at the same time.

What am I doing?

He wanted to stop, but his body was not listening. He leaned down and inhaled the scent of her hair again.

God, is this ... is this possible?

I'm more addicted to her scent than I had ever been to the smell of hard-boiledheroine.

After that thought, there was no going back. Sherlock knew what he NEEDED to do.

He pressed his lips to her cheek, gently, almost imperceptibly.

And it was so special and unfathomable for him. He could have kissed anybody si simply in his past. Parents, friends, girlfriends. Even Irene. But in this exact moment, with Joan, he felt different. So weak, he doubted with a hint of panic if he could handle it. But his lips stayed on her cheek as Joan opened her eyes, surprised by the irresistible rush of desire... Her heart started pounding against Sherlock's.

She felt the warm touch of his hand on one cheek and his lips on the other.

Silky.

Soft.

Joan sucked in a deep breath, as if she was winded.

And then, it was over.

He slowly took away his hand and his lips disappeared from her face.

Joan felt the heat on her cheeks. Sherlock looked at her and his heart immediately clutched at his quick understanding.

I can't believe I did this to her.

These last moments with her were so very different. Confidential, almost beyond his comprehension. He couldn't recognize himself.

"I'm sorry, Watson... Joan... I took advantage of the situation ... I got you embarrassed..."

She shook her head but felt she couldn't stay any longer without... without...

yearning.

"I must go," she said softly. He took a breath to say something but Joan didn't give him a chance. She was about to pass him but then she stopped. She quickly reached out her shaking hand and gave him her key to the brownstone.

"Are you sure you don't want to stay?" Sherlock asked quietly.

She nodded.

"It's my time to fall from your orbit," she whispered. "Everything had changed..."

After he was finally touching her, he couldn't disagree.

So he took the key from her and closed his eyes in pain.

Joan never touched him again. He listened to her footsteps quietly walking through the next room.

Then door of the brownstone opening and closing.

Silence.

Sherlock opened his eyes, gave an empty sight to Eric and then slumped into a chair, Watson's key still in his hand.

He dug his nails painfully into his palms when he realized how much he missed her presence, even if she had walked from his life just a few seconds ago.

He remembered the foolish words he told her once.

I feel liberated. I am, now and forever, post-loved.

"But are you really?" he whispered out loud to himself.

Ok, I think this is complete now but please don't be angry on me, I promise I will be kinder if you want me to be in my next story :)