Really, saving the leading scientist in alternate universe theory had been surprisingly interesting. Mycroft had reluctantly called them in when the man had disappeared. The plot on his life had been arranged by his ex-wife, interfered with by his girlfriend, and then he was kidnapped a second time by a group of eco-terrorists. It was a mess but they saved the hostages by messing with the powergrid in the research building. A little risky perhaps but there were lives at stake. Sherlock and John linger behind after the secret police clear the scene and take everyone into custody. Sherlock stayed to look at the strange technology that he normally wouldn't have access to. John stayed because Sherlock did and he had a bit of morbid curiosity about that portal looking device in the corner, seriously a portal? That's how they were the only two in the room when a dashboard of lights flashed and the machinery made a sound like a dying cat. Before they could run the portal upchucked a bright light that solidified into the silhouette of a man. Suddenly, a very confused young man holding a white mug in both hands appeared in front of them. Pale skin, dark curls, and intelligent eyes behind thick glasses looked at them with confusion. Sherlock stared, no doubt deducing. The stranger obviously wasn't a threat so John didn't know what to do. The thin twenty-something blinked at them then glanced around. His gaze came to rest on the portal behind him. This apparently clarified things for him because his posture visibly relaxed. "Ah, apparently their theory is correct. I'll have to reconsider their funding," he said calmly and took a sip from his mug. "Uh?" John glanced to Sherlock for help but the detective was tilting his head in concentration. "Hi. Who would you be?" "Proof of alternate dimensions." "You work for MI6, Quartermaster," Sherlock finally spoke. "Recent hire." "Right, you have a name?" John prompted. "Hamish. Hamish Watson-Holmes." He raised his eyebrows in amusement at their surprised expressions. "Wait, you're…" "Our son, obviously, or would be our son," Sherlock spoke over John's confusion. "And you're not married. That's not the wedding ring my Dad has," Hamish gestured to John's ring finger. "So, where you're from, I'm gay?" "No," Hamish no longer seemed to find this amusing. "Just willing to make an exception." "Right, what about Mary?" "Mary?" "My wife, 5' 11", blond hair, my age, really good with a gun, former CIA." "Hmm, sounds like the woman who killed Mr. Magnussen. Mycroft recruited her. I think she's training agents," Hamish shrugged. "I truly don't exist in this universe. That's surprisingly distressing." "Assuming there are infinite alternate parallel realities, nothing is constant," Sherlock answered. "Clearly," Hamish said a very Sherlock-like thing but with John's polite tone of voice. He had both Sherlock's fashion sense present in his suit pants, button-down shirt and tie and also John's fondness for tacky knitwear in the sweater vest he had chosen to wear. "Still it's disquieting to see you. You look exactly like my parents but aren't." "You aren't concerned with getting back?" Sherlock asked. "They assured me this test would last no more than fifteen minutes." "And you trust them?" "Only to know there will be consequences if I am misplaced for any considerable time." "Because you work for Mycroft," Sherlock snorted. "I was actually thinking of my parents. I was kidnapped once as a child, only once. And I work for Mycroft because it's nearly impossible to operate and maintain a supercomputer of my needs on a private salary." "Super computer?" John repeated. "Hacker, obviously," Sherlock said. Hamish held up one hand to show his calluses. "Our son's a hacker?" Despite the odd situation, there was a bit of humor in that. "That's a bit narrow, I prefer computer genius. I have plans to completely redefine programming before I'm thirty." Classical Sherlock cockiness but he spoke slowly and quietly. Sherlock gave a small smile that he reserved for things he found particularly cute. "So alternate realities exist," Hamish mused and took a sip from his labeled Q mug. "I suppose we could mine realities that don't have people in them for natural resources if our oil crisis truly does become dire it might be worth the energy output." The conversation was interrupted as the machines started to hum again. "Ah," Hamish glanced at the portal. "I do hope I won't see you again. Don't take that personally," he said in way of goodbye right before he transformed back into light and disappeared through the portal. The machines turned themselves back off, hopefully for good this time. John sighed and shook his head at how weird his life was. He then noticed Sherlock looking forlornly at the empty space Hamish had just vacated. "Sherlock?" The detective turned to look down at him with an expression that was almost regret or disappointment. "What?" That made John indignant. "He doesn't exist." "He has a family where he comes from," John said but he could understand the melancholy. The son they could have had seemed like a brilliant young man. John quickly shook his head with more force. He had his own future with Mary to worry about. "Could have beens" didn't help anyone.