It was in Arcadia that I made my first patrol. I was so young then and without name. Many others had chosen a title that suited them, but not me. Truthfully, it was because I hadn't found the right one yet.

The battle of Arcadia had been raging for weeks now, since they infiltrated the planet. It was our last stronghold, and now our greatest defeat. With the destruction of the battle TARDISes, the Daleks tore through our defenses as if we were infants. They came from the skies, sweeping through every block of every neighbourhood of every city with cold, calculated malice.

I had only joined the Arcadian Guard a week prior to the invasion. I knew that a great threat was coming but knowing and feeling are two very different things. I'd been given just enough time to train with minor weapons and learn formations before Arcadia was breeched. It wasn't enough.

All those formations, all those drills were pointless now. During the last explosion I had been separated from my squad. They could be anywhere. As for me? I was in the centre of it all, breathing in the sharp ash of the ruined buildings. They were once so majestic, a marvel to the universe. It almost made me laugh. If only they could see us now. We, the great Time Lords, trapped atop the fires of hell.

I moved down a side street, keeping my gun at my eyes. My hands shook against the metal, causing it to clink against my rings. I wasn't supposed to wear them but what difference would it make? If a Dalek were to incinerate me, they would disappear along with my body. No one would know the difference.

A great fire raged just ahead and to my left, the heat of which could be felt well through my armour. Through the heat waves I saw a small figure on the other side of the crossroads, clinging to the edge of a partially demolished wall.

I stepped out to cross the street when I heard a Dalek's voice from behind the fire. I shot back, crouching down against the wall to hide. My hearts were pounding through my chest plate, reverberating in my helmet like battle drums. I kept my gun pointed toward the street, preparing myself.

I waited and listened. After a moment the Dalek droned, "We are needed to the West. Retreat. Retreat!" Relieved, I breathed a shallow sigh of relief. Who knows how many were with him. I stayed still for a long minute, ensuring they were gone.

I stood up to run forward when I heard my gun go off.

I realized too late that I had my finger resting on the trigger. The blood drained from my hands, leaving them cold and clammy as I traced the trajectory of the bullet with my eyes.

The world slipped into shock, all noise around me melding into a piercing hum. The breath in my chest constricted. I felt my legs move toward the figure but I couldn't control them.

Shaky and barely breathing, I eventually reached him. My gun slipped out my hands, discarded a foot or so away. I didn't attempt to pick it up. Instead I placed both hands on his tiny chest to feel his hearts. Fear shook me. I could feel only one. The rhythm that pressed itself into my right palm was faint and slowly ebbing away. The bullet had pierced just inches above it.

His eyes were wide, like a spooked animal. His stare bore into me, filled with a knowing beyond his years. That fear, so cold, so palpable, told me what I was dreading – he could not regenerate. He kept staring at me, like he knew. That stare will always haunt me, the first tally on the list of lives I've been responsible for and taken.

I smoothed his hair and leaned down to whisper through forced breath. "I'm sorry. I'm so sorry."

The last beat left his heart and it was then that I wished I was a doctor.