(This takes place in the G1 continuity, with a few non-G1 characters. Canon with MvA. All the 'bots have modern day vehicle modes, some even have Bluetooth):
Location: Autobot Headquarters. The Ark, Mt. St. Hilary, Oregon, U.S.A. Earth.
Teletraan 1 was checking the monitor when there was a spike of energy in San Francisco. "Teletraan 1 to Optimus", he announced. "What's happening, Teletraan 1?" Optimus said. "There's a major energy spike in San Francisco. I suggest you get back here for briefing." "Will do. Autobots, return to base." Teletraan 1 then opened the Ground-Bridge and went to work to see what happened in San Francisco. "By the Allspark!" Ratchet said as the rest of the Autobots came from the Ground-Bridge. "What's happenin', old timer", asked Jazz. "There's a giant robot in San Francisco." "Megatron. AUTOBOTS! ROLL OUT!" Optimus yelled, but Bulkhead blocked the way out. "Wait, Optimus. I don't think that's a Decepticon." Just then, the proximity alert rang. "PRIME?!" Agent Fowler yelled. "There's a giant robot in San Francisco. We've had the entire city evacuated. Yet I'm told the president has ordered the Area Fif-" Just then, the signal cut off. "Agent Fowler? Are you still there?" Wheeljack asked, but got no response.
Optimus then proceeded to call Megatron. "Optimus?" Megatron said in surprise. "Long time no see, Buckethead," Jazz, Wheeljack and Bulkhead scowled in unison in the background. Everyone looked at them with annoyance. "A-Anyway" Optimus continued. "You didn't happen to deploy a giant robot TWICE THE SIZE of Devastator in San Francisco, did you?" "Oh, Primus, no!" Megatron replied. "Unless… SHOCKWAVE!" He yelled. Shockwave came running in. "Yes, Lord Megatron?" He said. "Go to Starscream's quarters and and use your club to knock him out and use the CPP to see if he deployed that giant robot in San Francisco." "Yessir." Shockwave then proceeded to do what he told him. Megatron then looked back back to Optimus and said "If Shockwave assures me that Starscream isn't responsible, then I will travel to that human city with you to fight it."
"Ratchet, stay here." Optimus said. "Everyone else, come with me. Blaster, call Omega Supreme, Metroplex, Aerialbots, and Protectobots. We may need them…" Teletraan 1 activated the Ground Bridge and they all teleported to San Francisco. When they got there, they saw the giant robot. Cliffjumper then cried out "Let's get 'im!" But Optimus stopped him. "Wait, Cliffjumper", he said. "Look." He pointed toward 4 life-forms. "What the hell is that blue blob doing?" asked Brawn. "Teletraan 1, status report," Optimus whispered into the comm. "It seems to be communicating with it," he reported. Just then, Jazz pointed, shouting, "BY THE ALLSPARK! LOOK AT THAT!" They all looked at the robot to see arms coming out of the sides of its body. Mirage then looked to see a giant woman running into the city. "Optimus." He called. "There's a giant woman running into the city." Optimus sighed. "Follow her, Mirage. Don't let her see you." Mirage then transformed and raced after her. However, nobody noticed Wheeljack slide away to help a human sized cockroach with upgrading a trolley with huge turbine engines.
They then saw the robot advancing on them. "AUTOBOTS, OPEN FIRE!" Optimus shouted. Almost right after, Sunstreaker stuttered, "Um… g-g-guys!" He turned and pointed to a Ground Bridge opening, which turned out to be the Decepticons, being Megatron, Soundwave, the Stunticons, Constructicons, and Combaticons. They then drew their guns, and the combiners combined and ran towards the giant robot. Omega Supreme arrived just in time to see them arrive. Devastator, Bruticus and Menasor stopped in there paths. They were worried. Omega saw them, and smiled a devilish look. "OMEGA SEES 'CONS! TARGETS ACQUIRED!" Some of the Decepticons were about to run for their lives, but Megatron ordered them not to worry. Omega powered up to full power, and almost shot at them, but just then turned his whole torso 180 degrees, and fired on the other huge alien robot. The combiners were relieved . Just then, the Aerialbots flew in. "Optimus, we're here." Silverbolt said. "Silverbolt," Optimus told him. "I need you to form Superion." "On it like planes to the sky, boss." Skydive said. They then flew at full speed towards the robot. Once they were a few meters away, they combined into Superion in mid-air, kicking the robot with all their might, but bounced of like it was nothing. Superion was confused. "It's been like that, flyboys." Devastator shouted at him. "Bruticus sad." Bruticus was crying oil. "Bruticus can't penetrate it." They seemed to have lost all hope.
Optimus and Megatron had an idea. They both ordered the combiners to retreat. They then ordered all the flyers to shoot at the neck. They responded, with Blastoff, Starscream and his seekers, Soundwave's flying cassettes, and the Aerialbots shooting at it. The robot was getting hurt. "Keep going." Thundercracker shouted. "We're half-way through!" Just then, the robot realized its pain, and swept at the fliers, making them flail to the ground. The medics arrived to patch them up. They then saw the robot back down, and head towards the city. Optimus was about to radio Mirage, but then he remembered he was on radio silence. "May Primus have mercy on us all," Ratchet said.
Mirage was following Ginormica to the city. He stepped quietly, hoping she wouldn't notice him. He then noticed that nobody was in the city anymore, so he turned visible, and followed her. She looked back, but he hid. Mirage then smelled the air, then realized something wasn't right. The girl was looking around, only to turn and see the giant robot behind a big skyscraper. Mirage then ran to her aid, only to be hit with a few pieces of debris. "Hi, there." He said. "Hi." She replied. "Please tell me you're one of the good guys." "Yup," he said, reassuringly. Looking back, he transformed and told her to get on. She got on and he told her to hang on tight. "What do you m.." she started, but Mirage quickly turned over to maximum overdrive, going fast, dodging flying debris and rubble. "So," Mirage started, as they were racing down the street. "What's your name?" "G-g-ginormica!" She strained to speak as the wind hit her face. Just then, a trolley was coming at them super fast. Mirage swerved to avoid it, but then told Ginormica to get off when he saw Wheeljack trailing it. He then raced after him, asking him what he was doing. Wheeljack responded, "Flashback time." He then opened his door and doused him with some flashback juice.
Wheeljack had just slipped away to help the human sized cockroach put jet engines on the trolley. The cockroach said he needed an F-15 Eagle fighter jet thruster. Wheeljack knew just the place he could get one. He turned back to see the Decepticons coming through their Ground Bridge. Excellent, He thought. Wheeljack took out his time-stopping device, but before he did, the cockroach man told him to wait. He saw something wrong with the wires. Wheeljack let him fix it, then was on his way.
He pressed the button, and the earth stood still. He then sped into the Decepticon Ground Bridge and went to Knockout's med-bay, only to see Knockout buffing himself. "No need to be THAT efficient." Wheeljack stated. He then continued in the direction of the spare parts room. He looked around. He saw some replacement doors for an array of cars, some spare tires and wheels, and some jet thrusters. "Bingo!" Wheeljack said. He grabbed F-15 Eagle thrusters, then was on his way. He came back through the Ground Bridge, pressing the time stopping device. Everything went back to normal, with the cockroach man seeing him, and thanking him.
It took them a few minutes, with Wheeljack stopping to transform and help his friends up when they were swept away by the huge robot. The cockroach man, identifying himself as Dr. Cockroach, continued working on it. He then went back, with him being finished. They then put it on the road, with it going SUPER slow, with it not being on the rails. Wheeljack pushed it, but Dr. Cockroach insisted he do it, with WJ following. He then went to the top of a big hill, and Dr. Cockroach flipped the switch. The jet engines started up then failed. "Hmm," Wheeljack said. "Now I could have sworn that I [Insert scientific term here], but i guess if I..." Just then, the jet engines sprung into action, spewing fire into WJ's face. The trolley lept into action, flying down the hill, bumping up and down when it hit flat parts. WJ followed it, and that's "how I got here."
Wow." Mirage said. "However, you must not be happy that another one of your inventions blew up in your face." "Yeah.. I guess not." Just then, they were right below the robot. The left foot rose, and the blue blob thing leapt off the foot and went straight back into the trolley, taking Dr. Cockroach and Link (Who the trolley hit once it hit the 4th or 5th bump.) with him. "Oh no." Wheeljack and Mirage said in unison. They screeched to a halt, and saw the 3 monsters, and the trolley, fly off the land and splash into the sea. Mirage then looked toward the Golden Gate Bridge, and saw Ginormica "skating" towards it. The robot was now in the middle of the sea, halfway between the land and the bridge.
Wheeljack radioed Optimus. "Um, Optimus?" "What is it, Wheeljack?" Optimus answered. "If this has anything to do with the robot being near the bridge, we are already there. We're trying to get it's attention away from the humans." "Well, here's what you gotta do. Try to get one of the smaller bots or even a human in one of the robot's openings and get him to the brain module to overload it. Once you do that, you should be able to defeat it." Optimus thought for a moment. Then, he called for Sea Spray. "Sea Spray, get Spike in there. Go into one of the robot's legs and find your way to the brain module. I'll patch you in with Wheeljack." Sea Spray got Spike and raced him to the robot. When he got there, he jumped, transformed in midair, an threw Spike up into one of the openings.
Once inside, Spike was patched in to Wheeljack. He carefully guided him through the robot. When he was in the chest, there was a big shuddering in the robot. He looked through a hole in the chest and saw a giant mouth looking opening with large rotating spikes. He saw Ginormica saving a few cars from plummeting into the water below. Nice save, he thought. He then made his way up to the head, and found the brain module. However, he was a little late. Dr. Cockroach was unconscious on the floor after a small explosion knocked him out. He looked out the eye and saw a large light hypnotizing a large grub-looking monster. He then called to Wheeljack, "What should I do?" He asked. Wheeljack told him what to do in great detail. First, he shut off the giant light. But, before he could do the next step, Wheeljack told him to get out of there. He grabbed Dr. Cockroach, and ran out the arm. They landed on the collapsing Golden Gate Bridge, and ran with the others. He spotted Blurr and told him to wait. He got inside, and raced off to meet the others. Looking back, he saw the bridge collapse entirely. A part of the bridge fell down and decapitated the robot, with sparks flying everywhere.
Back at the base, Optimus congratulated everyone, including the monsters. "Thanks," Ginormica said, "But I gotta go see my parents." "Rachet will take you there by the GroundBridge