Originally written for the February 2008 Springkink round in response to this prompt: Optimus Prime/Starscream: battle lust – The world is in our hands.
The Power in Your Hands
The ground just to Prime's left exploded; a purposeful miss, meant to drive him, as all the others had. He let his pursuer push him through the hills around the summer-dry riverbed where Autobot and Decepticon forces clashed once again. Prime could see the battle raging on below him, flashes of color filtering through the rugged pine trees of Oregon's high desert.
Starscream had been dogging his every step since the battle's start. Prime had finally fallen back into the sparse trees, where the Air Commander would either loose the advantage of flight or he'd retreat. He hadn't retreated.
Prime dodged around another tree, crouching low. The branches started high, but he was rather tall according to the scale of this world, and even Cybertronians preferred to avoid a facefull of needles. One of Starscream's null rays hit a little too close. Prime's right arm went sensor-dead, temporarily numb, but the Seeker had finally come that little bit closer.
Prime grabbed the shoulder-mounted weapon with his working hand and pulled, bringing Starscream's cockpit straight down onto his rising knee. Hairline fractures crackled and crunched, snaking across the canopy, but it didn't shatter. Starscream lunged forward, recovering quickly. Prime lost his one-legged balance, sending them both crashing towards the ground. Shrill, distinctive laughter rang in his audios. Prime still had his grip on Starscream's upper arm. He pulled, turning them as they fell so that he landed on top, both their heads pointed down the hill. Dusty dirt flew up in a cloud around them, coating their armor.
Starscream's laughter morphed abruptly to a snarl. The Air Commander bent a knee and fired a heel-thruster straight down into the ground. More dirt flew, what little grass there was filling the air with the stench of burning organic material before the miniature fires snuffed themselves out. Optimus felt his lower body beginning to lift off the ground. He shifted his weight back slightly to compensate. Starscream kicked off a tree trunk and engaged his other thruster full blast, the force of it pushing him into a backwards flip down the hill that carried Prime along for the ride.
Optimus curved his neck, absorbing the impact through his shoulders, one leg coming down bent at the knee to keep Starscream from pinning him completely. A hot thruster burned into the side of his ankle joint, sending his leg sideways and allowing the Decepticon to come fully down on top of him.
"Hah!" Starscream gloated. "This is the power of the great Optimus Prime?" He pressed in, damaged cockpit crunching and squealing unpleasantly as he rubbed against Prime's chest plating. With their chests pressed together this intimately close, Optimus could feel Starscream's energy field, running as hot and quick as his own, drunk on battle lust. His engine revved in response, moving towards synchronization with disconcerting readiness. They grappled briefly, Prime pressing upward with his left arm and Starscream bearing down with the entirety of his weight. "You're mine," he hissed, face inches away from Optimus' battle mask, intakes increasing their pitch at the strain of attempting to keep Prime's larger bulk laid flat.
Feeling returned to his right arm, bringing with it the knowledge of a sizeable rock nudged right up against his fingers. Prime grabbed it, slamming it against the vents on the side of the Seeker's helm. Starscream shrieked and reared back. The rock shattered under the force of the blow, jagged shrapnel flying everywhere. Both Starscream's null rays fired, one of them plowing into the ground just next to the Autobot Commander's head. His audios buzzed, radio receiver splashing static across his mind. He shoved upwards with a shoulder, using his arms to push away from the ground until he'd given himself enough clearance to punch.
Starscream's cockpit finally shattered.
The Seeker choked, for once silent, straddling the lap of his enemy, Prime's hand lodged in his chest. His energy field flared around the intrusion. Optimus felt something within himself building. It was a familiar feeling, only this time tinged with something else that made it nigh unrecognizable. Something powerful and violent, alarmingly close to breaking free of conscious control.
Starscream locked optics with him, a gleam in them that sent a thrill of terror and lust shooting through Optimus.
He knew what was coming. He knew. But he couldn't bring himself to move his hand.
Starscream's energy field spiked, colored with a tinge of deliberately exaggerated aggression. Later, Prime would tell himself that answering pulse from his own body came too quickly to hold in.
Starscream's back arched even as he leaned forward into Prime's hand, a different kind of shriek tearing itself from his vocalizer. Optimus groaned, stiffening as he fought himself.
An explosion, larger than the rest, rocked the valley below.
"Decepticons, retreat!" Megatron's bellow reached them through the trees and weapons fire. Prime jerked back, shoved Starscream away by his shoulders, and staggered to his feet. The Air Commander leered up at him from the ground, grin sharp and predatory.
"Until next time, Prime," he hissed, before the bravado vanished and he scrambled to his feet, half running and half crawling towards the tree line and the freedom of the air. Prime watched him go, staying where he was until the phantom energy surges had faded to nothing.