The Titans had originally come to Detroit when Cyborg received an invitation to Sumdac Tower from Professor Isaac Sumdac, an old friend of Cyborg's father. It was supposed to be just that, a simple visit. They hadn't expected to meet them.
"Autobots, TRANSFORM!" ordered a red fire truck which didn't have a driver. All of a sudden, it transformed into a tall humanoid robot with a blue helmet and kind face, bearing an emblem resembling a blocky face on his left shoulder. 4 other vehicles; a yellow car, a black and gold bike, a green military truck, and a red and white ambulance also transformed, all of them bearing the same symbol on a part of their body.
The Titans stood speechless at the sight.
"Prowl, Bulkhead, throw it off its feet!" the big red fire truck-robot ordered. The motorbike-robot, known as Prowl, and the military truck robot, known as Bulkhead, nodded and obeyed their leader's command before rushing forward. While the large green one was big and strong, the black and gold one was sleek and swift, able to leap high into the air to launch a pair of shuriken-like weapons at the rampaging robot. The larger robot, the largest of them, threw a wrecking ball that knocked the rampaging robot backwards.
The rampaging robot had malfunctioned and escaped from Sumdac Tower. The Titans had been ready to fight until these transforming robots appeared.
"OK, Prime, let me go in!" a small yellow robot with racing stripes spoke eagerly.
"Negative, Bumblebee," the fire truck robot, Prime, shook his head. "You and Ratchet are going to keep the civilians safe."
"And you?"
A faceplate slid over Prime's face. He then reached behind his back and pulled out an axe.
"I'm going in personally!" said Prime before rushing towards the robot. Bumblebee crossed his arms.
"Aw, you're no fun!" Bumblebee said before getting conked on the head. "Hey!"
"Just do as Prime says," the ambulance robot, known as Ratchet, said.
"No way!" Bumblebee exclaimed defiantly. "I'm going in!" The wheels on his heels spun as he charged towards the robot.
"Stubborn young bot," Ratchet grumbled as Bumblebee unleashed his 'stingers' from his hands and fired electrical blasts at the robot.
"I thought I told you to stay back!" Optimus yelled, barely avoiding a swipe from the berserking robot.
"Sorry, Optimus, but I'm looking for action!" Bumblebee shouted but then he looked up. "Oh, slag." The foot of the giant rampaging robot dropped down on the yellow bot and he barely missed getting stomped since Optimus Prime, the fire truck-robot's full name, was able to push him out of the way. Optimus could now see the problem as he saw the robot's head.
"Autobots, attack the head!" Optimus ordered. Bulk-Head sent his wrecking ball at the head, denting it. Prowl threw his shurikens, causing them to get imbedded. Prime then leapt onto Bulkhead's shoulders and jumped up before swinging his axe hard at its head. Bumblebee shot a powerful electrical blast at the robot's head and then finally Ratchet finished it off by creating a magnetic field around the head, ripping it clean of its shoulders.
"It's coming down!!!" Bumblebee shouted as the robot was ready to fall. It fell with a crash, the wires at its neck sparking.
The Titans were in awe as the citizens applauded. "Who…what are they?" Robin asked.
A little girl, Sari Sumdac, turned towards Robin and said, "Those are the Autobots."