I've had the idea for this story for some time. I actually got the idea from the song, Cosmic Castaway by Electrasy from the movie Titan AE. I just never knew how to start it until now. It is totally AU. Below are the lyrics for the song. Listen to it if you get the chance.

In depth summary: Sentinel Prime is the military leader on Cybertron. He reports to the High Council, the collective leadership of Cybertron. Megatron and his Decepticons have been an annoyance for several vorns until now. As a result, a civil war erupts across the once peaceful planet. Sentinel is forced to send his son, Optimus, to safe world until he is either of age to fight in battle or the war is over. The ship is attacked before it even reaches its intended destination. Sentinel and Thea, his bonded, believe their son had perished in the attack. Only Optimus did survive. He grows up not knowing exactly who he is, traveling from one planet to another with his caretakers. The only memories are deep within his spark, the love he felt from his real mother and father. This is his journey through the stars and eventually to the home where he belongs.

a/n: some Cybertronian time references for the story

Astrosecond- 0.25 of a second

Nano-klick- one second

Klick- one minute

Breem- one hour

Jour – one day (36 Breems)

Deca-Cycle – one week (10 Jours)

Orn – one month (50 Jours)

Vorn - one year (14 Orns)

Cosmic Castaway

Lose my head to the chemical freeway
Comin' up on overload
In a mystic new dimension
Purify and sanctify me
What, so I'm in no end game
Move my piece right off the board
Losing sure is easy so I am no more

But I'm not broken, in my dream I win
In here I'm nothing, a Cosmic Castaway

In my head I'm a chemical dreamer
Speed up to burn out mode
Comin' up in the 5th dimension
Beautify don't crucify me, yeah
So I need no mind game poisoning my lonely soul
Losing sure is easy so I am no more

But I'm not broken, in my dream I win
And I take over, coz I'm no loser
And I'm in and you're not, bad dreams don't stop
But I'm all screwed up, a Cosmic Castaway
a Cosmic Castaway, a Cosmic Castaway

And I want but have not
Bad dreams, lust thoughts
In here with no pain, you hurt me again
And I want but have none
I should beat the alien
But here I'm no one, a Cosmic Castaway
a Cosmic Castaway, a Cosmic Castaway
a Cosmic Castaway

Sentinel Prime

The predawn hour was peaceful and quiet. It always was whenever I woke from recharge. My gaze fell upon the open window. The cool early morning breeze wafts in. My audio receptors picked up the faint hum of the city.

Yes, even at this height, some fifty stories up from ground level, I hear the hum of Iacon City. Being Prime has its advantages. I'm allowed the room with the best view anywhere on Cybertron. It takes me away from the noise and of a wide awake city yet allows me the comfort of hearing the city's pulse in the dead of night when everything else was quiet.

Only this morning a new sound fills my audio receptors. The silence is broken by the sparkling waking. Soft beeps, warbles and a barely audible whistle emanate from the recharge crib. I can even hear the faint rustling of tiny arms and legs.

I smile, gently sliding from beneath my femme's arm. Ever so quietly I tread towards the recharge crib in hopes to watch the sparkling without him noticing me yet.

My smile grows wider.

Peering over the rim of his crib I see his beautiful blue optics focused on the toy I had given him. He is only a few days old and doesn't yet have the strength to roll over or reach for the toy. But it does not stop my son from trying.

My chest swells with pride to see he is already so strong willed and determined to do things on his own. His tiny arms and legs kick and move about as he tries to will his tiny body to do as he commands. He manages to touch the toy with his tiny fingers.

A loud squawk erupts from him as he grows frustrated making me chuckle to myself.

Tiny blue orbs quickly turn in my direction and lock onto me. A flurry of excitement escapes him as his arms reach for me, his legs kicking wildy, and…my spark melts…his first smile. After all that I could not deny him a reward.

My large hands delicately lift my little mech up and bring him close to my chest. I cradle my son protectively in one arm and head to the balcony to show him his first view of our world, of his home.

The city is lit up, as it always is. But only at night can one appreciate its beauty. It is simply…breath taking. A long appreciative whistle sounds from my sparkling.

"Exactly," I smiled. "Do you see over there, my son?" I pointed. "That's Decagon. I often work there. Perhaps one day you will work there with me. Would you like that?"

He giggles wildly, blinking his optic covers at me. His tiny hand grasps tightly onto my extended finger that I offer him.

"I take that as a yes," I cooed to him, nuzzling his face affectionately with my nose.

"Primus, he's already an early riser just like his father."

Surprised I turned to see my bonded sparkmate, Thea, standing in the doorframe. Her slender protoform accentuated in the soft fading glow of the setting moons.

"Would you expect anything less from our son?"

"No," she smiled, closing the gap between us. Her hand caressing the sparkling's smooth head, making him purr loudly, his optics dimming slightly. "I expect he'll be as noble and brave as his father."

"Ah, but he'll be as compassionate and caring as you, my love."

My sparkmate's smile fades as she stares intently up at me.

"Regardless of what he grows up to be, please, keep him safe. Give him the means to defend himself at all costs."

"I thought you didn't want him to grow up be a soldier."

"I don't. But he is the son of a Prime. I'm frightened to think of all the possible dangers that may be ahead of him because of who he is."

"You know I will do anything to protect our son."

"Sentinel, promise me that he will be safe from harm," she begged, tears spilling from her optics.

My love Thea has never been so frightened. Not even on the battle field. She was no timid femme. One of the things I loved most about her was her inner strength to face her fears and conquer them.

Yet, I can understand why she is afraid now. It is a new fear to both of us as we have only been parents for a few days now. We cannot help but worry for our son. I love him more than life itself and would do anything in my powers to protect him.

"I cannot promise that he will be safe from harm his entire life. But he will grow to be big and strong, a most capable warrior. He will always be looked after, even if I cannot keep my optics on him myself. That is all I can promise. Will that suffice?"

Thea nodded at me, her hands reaching to take our son into her arms. The tiny mech gurgled and cooed up at his mother.

"I guess I shouldn't worry so much," she smiled, her optics never leaving the sparklings. "He will have plenty of guardians on the base to look after him."

"And he will have us to love him and guide him," I added, possessively cradling his head in the palm of my hand. "I have decided upon a name for him."

"You decided?" she questioned, raising an optic ridge at me. "What happened to us deciding on a name, together?"

"I know it is a name you will like," I smiled brightly. "It came to me as I was returning home from the base last night."

"I sincerely hope it's not one of the suggested names Ironhide gave you."

"No, it's not," I chuckled.

"Thank Primus. He may be one of your best officers on the battlefield but he has the imagination of a drone!"

"I'll tell him you said that," I laughed heartily.

"I've told him myself on a number of occasions already," she smirked at me which only made me laugh harder. "It never sinks into that thick plated head of his."

"My fearless femme quick to kick any mechs aft and never afraid to tell it like it is."

"You wouldn't have me any other way," she smiled warmly up at me.

"No, I wouldn't," I sighed wrapping an arm around her, pulling her closer to me.

"So, am I going to have to kick your aft to get you to tell me what name you've picked for our son?"

I look fondly at the tiny mech in her arms. His optics intently focused on his mother. His tiny hands reach up for her. The bond between them is strong. I feel it in my spark whenever Thea holds him.

She gazes up at me in anticipation. The sun is now peaking over the horizon, shedding new light on my sparkmate and sparkling. At that moment, she has never looked so beautiful. My sparkmate…the mother of my son.

I stand tall and proud, my optics locked onto her gently blue orbs.

"I wish for him to be called…Optimus."

Thea remains silent as she takes in what I've told her. Her gaze returns to our son. I eagerly wait for her response, anxious to know what she thinks of it.

I do not even know where the name came from. Perhaps from Primus himself. It just suddenly came to me as my cerebral processor wandered aimlessly while I rode the transport home. I very rarely allow my processor to do such a thing. It is always calculating something.

"Optimus," she speaks softly, her delicate fingers caressing his little face plates. "Sounds strong, noble, brave…caring. I like it."

Giggles erupted loudly from the sparkling.

"I guess he likes it too," she smiled. "Do you like it…Optimus?"

His optic covers blink as rapidly as the series of clicks he spews out in response. He grows silent for a moment then grins up at us.

"I take that as a yes, my son," I sighed contently.

On impulse I gently take him from his mother's arms and hold him high in the air above my head. His optics take in all that is around us as the sun rises. I smile with such pride as he shows no fear at being so high. His small form is completely relaxed in my hands. Even his feet dangle calmly.

For the first time, as his bright blue optics find mine, I feel his love within my spark. I've always extended my love to him as his tiny spark developed within Thea's reproduction chamber in hope for this exact moment. It wasn't until he was born that he'd reach back to me with curiosity. He was still trying to decide who I was.

The recognition was there in his face, the love was there in his spark. He finally understood who I was to him. He finally saw me as his father.

Tears filled my optics as I cradle him in one arm. I pull Thea close with the other, kissing her forehead. The love for my family overwhelms me during the moment. A moment in my long life that I thought I never desired until I fell in love with Thea a few vorns ago. A moment I had been waiting from ever since I learned I was a father.

"Optimus, my son…how I love you so much too," I whispered, pressing my cheek to his. "You and your mother are the two most precious sparks in the universe to me. Mine would literally be lost without just one of you."

Up next: A few familiar mechs we all love and adore get to meet their future Prime.