Anja opened her mouth to reply, then looked around and realised I was already gone.

I cautiously navigated my way around all the cheering, screaming Gryffindors, who had swarmed out onto the pitch.

Crookshanks and the dog trotted away from the castle.

I followed them.

After a few minutes of walking through the grounds, we approached a tree. And not just any tree – a tree whose branches were waving around wildly.

The Whomping Willow.

I expected the two animals to go straight past it, but instead Crookshanks ran straight towards it and pressed his paws onto a knot at the base of the tree. Immediately, the Willow’s limbs stopped moving.

I moved forward.

There appeared to be a passageway at the bottom of the trunk. Both Crookshanks and the dog entered it. I followed, striving hard to stay entirely hidden under the Invisibility Cloak. The animals went along the tunnel and we came out in a run-down looking place.

The Shrieking Shack?

Crookshanks settled down on a chair. I stood awkwardly at the edge of the room. The dog sat down on the floor.

Only, it wasn’t a dog anymore.

It was an Animagus, I realised in horror. And its human form was none other than Sirius Black.

“Holy Merlin!” I gasped. I clapped my hands to my mouth, but it was too late.

Sirius Black stood up. His clothes were dirty, as was his skin. He glanced around. “Either there is a foul-mouthed ghost in here, or someone is wearing an Invisibility Cloak.” He turned to Crookshanks. “What do you think?”

Crookshanks didn’t reply – why would he? He was a cat, after all. He simply walked over to me and wrapped himself around my ankles, purring.

There was no point hiding any longer. Scowling, I pulled off my Cloak.

Sirius Black stared at me, taking in my Slytherin Quidditch robes and my features for a minute or so.

But, despite all that, only one word escaped him.

“Lily?”

Wow, he really was mad.

He must have known my mother, but mistaking a 13-year-old girl for her mother?

“No, Lily Evans is my mother. I’m Jade. Jade Evans.”

He stepped forward and looked directly into my eyes for a few seconds. Then he groaned. “Don’t tell me…Snape?”

I nodded, perfectly aware of the enmity between this man and my father. “Yes.”

He looked furious. “He sent you to follow me?”

I found myself being completely honest with a convicted murderer as I shook my head. “No. No-one knows I’m here. Besides, neither Father nor I knew that dog was actually you.”

Why was I confiding in him? He was a murderer! He had killed a number of Muggles and a wizard who was his friend!

Though, admittedly, that friend had been a Death Eater…

Black turned away and looked back at Crookshanks, who was curled up on the seat again.

I stepped forward. “You’re a murderer!”

He looked amused. “No, I am not. I can explain,” he interrupted, holding up a hand. “Peter Pettigrew was a Death Eater.”

“I know,” I muttered impatiently. “Father told me.”

He looked shocked, then he smirked. “I knew he was a Death Eater…” His smirk faded. “Anyway, Lily and James were informed that…Voldemort…was after them. So they made me their Secret Keeper. However, I convinced them to change to Peter at the last minute. He…he sold them to him. Voldemort.”

I grimaced. “That’s horrible. But you…you still killed him!”

He shook his head. “If only. I realised what he had done. I tracked him down and found him the very next day. However, he pretended that I’d been the Secret Keeper. He blew up the street. He cut off one of his fingers and turned into a rat, then fled.”

Sirius Black really was innocent. He had been all this time.

There was just one detail he had forgotten to mention. “But what happened to Pettigrew?”

He spread his hands and shrugged. “He disappeared. But this clever cat here helped me to find him. Still in rat form. He is currently at Hogwarts, the pet of a young wizard named Ronald Weasley.”

I thought I remembered seeing Ron with a rat, once or twice…

I looked at my watch. 3:30 pm.

“So,” I worked out slowly, “you’re an unregistered Animagus?”

He nodded.

Slowly, a smile spread across my face.

“How do you become an Animagus?”