IT HAPPENED WITHOUT US
This is an AU based on the third-season episode entitled "The Anti-Matter Man."
An accidental link had been created with the parallel, antimatter universe, in which all of the counterparts of our people are evil. The wicked John Robinson had been here in our universe, but had followed Smith when he had seen him enter the gateway into the negative universe. Smith had become aware of the dangerous man pursuing him, and had begun to run through the weird, surrealistic scenery.
Smith's heart pounded in time with the pounding footsteps behind him. Then, he saw an apparition walking toward him from up ahead of him. It was a bearded Don West. And he was striding determinedly toward Smith. Panicked, Smith skidded to a halt. He realized that no one could grow a beard that fast, and that it therefore had to be the evil Don West. That is, Smith thought to himself, if the normal Don West could possibly be thought of as good. But the moment that Smith saw West's eyes, he knew the difference. The cold, calculating hatred in this one's eyes made the regular Don West resemble a choir-boy by comparison. Frantically, Smith turned back the way that he'd come. He had all but forgotten the evil John Robinson on his trail. But Smith only ran a few steps before he was cruelly reminded, as the pursuing enemy came into sight. Confused and horrified, Smith turned once again to the original direction, saw the bearded monster again, and stopped cold. While his feet no longer moved, his head swiveled wildly from one to the other. As the two dangerous men closed in on him, Smith let out a blood-curdling scream.
A scream that should not have been audible from our side of the crossover, but was. A scream that sent the real John Robinson and the real Don West into action. They charged through the gap and into the eerie landscape.
Meanwhile, the wicked pair was mercilessly beating and scolding Smith, punctuating their criticism with punches.
"I know you!" West hit him in the stomach. "The same spineless, sniveling coward...." He struck him in the chest. "...that we have in our universe!" He punched him in the nose.
"I followed you back in here...." Robinson hit him in the eye. "...so I could get you alone...." He punched him in the jaw. "...you conniving little weasel!" He struck him in the back.
They finally stood aside and let Smith fall, which he'd already been trying to do at least three punches back during the fray.
The real John and Don ran up on the scene.
A disoriented, semi-conscious Smith tried to hold his wavering head straight, stared, blinked, and stared again. "Double trouble," he muttered and passed out on them.
Don lit into his double, and John attacked his duplicate. Their anger at Smith's obvious condition gave them an added edge over opponents who otherwise would have been an exact match in strength and skill. The two may not have had a great love for Smith, but he was still one of their people, and they still had enough fondness for him not to wish a punishment that severe on him. Their fury bought their victory. The wicked pair lay defeated and unconscious.
The real John and Don went and stood over Smith, looking down at him regretfully. Presently, Smith came to, and looked back up at them with glazed and bleary eyes. They bent down to him. Smith studied their faces, especially West's, and mumbled, "No beard. Good."
Don made a half-hearted attempt to make light of the situation. "Well, whaddyya know? You've always feared we'd beat you up, and now it happened without us!"
Smith gave no response, but just continued to look up at both of them through liquid eyes in a bruised, bloody face. He was obviously in shock.
Don clearly regretted his feeble attempt at lightness, and looked infinitely sad. John's pained eyes were hurting intensely for Smith. Each of them reached and took one of Smith's hands in his.
They let him lie there until he felt that he could endure being moved. Then, they lifted him with great care, and took turns gently carrying him on the long path back to the normal universe.