Then, just as I considered falling back on the noble, timeless technique of screaming very loudly, something astonishing happened.

A girl ran past me. With a sword.

She paused before she jumped onto the bus, looked back at me over her shoulder, and winked. Winked.

Then she leaped on board and faced down the Asura. She was barely older than I was, but she was ferocious, all sharp lines and elbows and edges, the sword as much a part of her as her hands. I watched in awe as she looked the demon in the eye and didn’t even tremble.

“You,” the Asura spat the word, punctuated by a puff of smoke, “you’re here. You are relentless.”

The girl smiled, but it was the least friendly smile I had ever seen. “Did you really think I wouldn’t follow you? Go back to Mysore, Asura. Go back and tell your king we won’t let him return to this world.”

The Asura growled and sprang at her. The girl darted out of the way. She dragged the bleating bus driver out of his seat and pushed him out of the bus. The doors hissed shut, cutting us off from both girl and demon.

“Oi!” the bus driver shouted. “I’ll call the police, don’t think I won’t!”

I ignored his shouts, and the flurry of phone-camera flashes, and ran to the bus. I pressed my hands to the glass of the doors, my heart like thunder in my ears. I wanted to help, but I didn’t know how.

All I could do was watch as a demon and a girl fought a battle inside a red London bus.

They moved so fast that sometimes they weren’t much more than a blur. The only way I could make sense of it was by holding individual moments still, like sketches on a page. Her sword met the blade of his tail. His teeth snapped a hairsbreadth from her face. White snakes of his smoke wrapped around them. His scales gleamed too bright in the harsh lights of the bus. And the girl, somehow, held her own against the Asura. More than that, even. She was glorious. She faced him like she had been born to fight demons.

Like she had been born to fight demons.

I stared at her. At the brown skin. At the shiny dark hair cut in a sharp bob below her chin. At the brown eyes that glittered with joy and mischief I had put there. I knew that face. I knew her.

She hadn’t been born, had she? She had come from the same place the Asura had. My sketchbook. I had made her.

The Asura lashed out with the jagged tail I had given him. The girl dodged and danced from seat to aisle to seat, always just out of his reach. The Asura snarled and leaped right over the seats. He swiped a powerful, clawed foreleg at her and knocked her onto the floor. I gasped as he loomed over her, his smoke darkening to crimson as he prepared to breathe fire.