21XX A.D...about a year after the events in MMX4...

In a dark, grimy corridor somewhere under the city of Manhattan, a strange purple light emanates. The source of the light reveals itself to be a round, purple vortex made up of the fabric of time and space. From this doorway a robot wearing black armor with purple and grey trimmings, a black helmet with purple fins, and a purple jet pack resembling bat wings, emerges. His face looks like any ordinary human with the exception of the twin battle scars running from his eyes down his cheeks.

Bass looked around the hallway with a sort of grim amusement. "Hmm...Looks like it works. Th' ol' crackpot may be goin' senile, but he can come up with some cool gadgets." The portal closed behind the ebony robot as he started to glow. The light grew so bright that it would have been impossible for anyone to see him in the center of it, had anyone been looking. When the light died off, two figures stood in the hallway. Bass's once purple trimmings were now a startling gold, and the bat wings had disappeared. Next to him was a large, purple, robotic wolf. Bass scratched his companion behind its ears and looked around. "Interesting place we landed, isn't it, Treble?" Treble wasn't listening since Bass found that particular spot at the base of his ears that was wired directly to the pleasure center in his robotic brain. "Seems ta be only an old sewer tunnel, but...Hello, what's this?"

Bass spotted some sort of symbol painted on the wall. Bass stopped scratching Treble's head to go check it out. When he got up to it, he wiped some dust off that had accumulated on the walls and just looked at it. A rather strange symbol actually. It certainly wasn't the stylized 'W' that was plastered all over Wily's creations. It looked more like an X that had been drawn to look like some sort of deadly beast. "Not exactly somethin' I'd come up with, but...it's sorta cool." Then Bass turned around with a start. He heard voices coming his way!

"I still don't see why Sigma wanted US to come investigate something as minor as an energy surge," a rather juvenile voice said. "I mean, we're the best Mavericks at his command, and it's not like this is an uncommon occurrence or anything!"

Bass was too busy trying in vain to find a hiding spot that he didn't stop to ponder at the unknown words and names he heard.

A voice that sounded like a cross between a rasp, a hiss, and a growl answered. "Well, this one is quite different! Sigma said that this energy surge was the biggest, most unique, and possibly dangerous one he's ever seen. Besides, we were the closest to this spot when the call went out." There was no way to hide, so Bass just stood in the middle of the hallway waiting for the unknown to come to him while charging up his arm cannon. Treble growled as they came nearer. To Bass' surprise, it was two robots. The shorter one was a rotund little fellow wearing yellow armor, but his companion really caught his attention. He was about the same height as Bass, with purple armor with grey trimmings, a rather large cannon mounted on his shoulder, and a purple helmet covering his face that made him look like Boba Fett. He had the same symbol on his head as was on the wall. Both mysterious robots stopped short at the sight of the robot and his dog. "What the...?" the yellow one said in surprise before Bass wrapped his left arm around his neck and pointed his arm cannon at his head. "Now, tell me where I am and how to get out or this yellow banana gets it!" Bass threatened.

Bass had the impression that the masked one was amused at the situation. "That," he rasped/hiss/growled, "was a big mistake." Suddenly, in a brilliant flash of light, the little one was gone to be replaced by a robot that seemed to be mostly made of some kind of gel. Bass gagged as "Jello Man" reached over and grasped the black and gold robot's neck, then swung his victim around in front of him. "Can I kill 'im, Vile?" he asked with anticipation.

"No, Double," the one called Vile said, "I don't think he's a hunter. In fact, he may not even be a Reploid." Hunter? Reploid? "What are these things talkin' about?" Bass thought. "Oh?" Double replied, "And what is he?" Vile looked at Bass. "I think he's a 'bioroid', you know, a 'living machine.' Robots with free wills before robots became Reploids. And if he is, we need to study him a little first."

"And how do you know he's a bioroid?"

"Just call it a...hunch! We'd better take him to Sigma." Double dropped Bass, and before the black robot could vent his anger on the gelatinous robot, he felt a searing pain coursing throughout his body. After a few seconds, he fell to the ground, seemingly unconscious. Vile and Double both knew, however, that he was awake, but totally paralyzed. Smoke rose lazily from Vile's shoulder cannon. Treble looked at his master on the ground, then looked at Vile. With a huge growl, he was in the air with Vile's death on his mind. He was taken down easily by another shot from Vile. Then Double slung one robot over each shoulder and let Vile lead him down the hallway.