Truth and Proof.

"I believe you," Caster said as soon as Sirius had finished. The boy looked enthralled and Sirius couldn't fail to notice how the boy's eyes had a strange shiny quality which made Sirius wonder if he might cry. Sirius turned away. Caster looked so much like Regulus and in so many ways Sirius still wished that, somehow, it could be Regulus who was telling him that he believed him with tears in his eyes.

"What proof have you got?" Leo asked sceptically, his head tilted arrogantly. Sirius sighed; this boy was beginning to annoy him.

" Well, I'm afraid that the main piece of proof I could have given you escaped but certain aspects of the story will add up with what you already know."

"Such as?"

"I believe Remus- professor Lupin was revealed to be a werewolf."

Leo raised his eyebrows thoughtfully.

"And if you went into the archives and got a copy of the Prophet from the 23rd of June you will see Pettigrew in his Animagus form and his index finger is missing which fits in with the story- You've probably heard how they only found his finger after his murder."

"See- it has to be true." Caster said excitedly.

"And then there's the fact that I'm an Animagus. There are also several reliable people who can confirm this- Remus, Harry and his friends-"

"Harry Potter?"

Sirius nodded. "And I'm sure that if needed Dumbledore would even support my story. I would happily allow you to question any of these people. If that's what needed to prove my innocence to you."

Leo still looked sceptical. "I'd like to have time to think about this, after all, you could be trying to trick us. I want to be able to consider other possibilities."

" Crikey, you're worse than Mad-Eye Moody." Sirius had not been expecting this, thank goodness he hadn't be faced with so much scrutiny in the shrieking shack.

"He always likes to have the time to think things through," Christine said quietly, "Well, things like this anyway."

"I don't know why you have to think about it so much- for the first time in our lives we have a father- an actual father."

"And if he is we'll be stuck with him for many years to come but if not I'd rather not have an impostor- or worse a murderer."

"He would still be our father- at least we know who he is"

"Caster-sugar, honey, there is something else I need to tell you," Christine said uncomfortably.

"What? You not leaving are you?" he glared at Sirius accusingly.

"No, it's just… Sirius isn't your father."

"But you said-" Leo looked up, looking completely confused.

"No. Leo- Sirius is your father but he's not Caster's"

Sirius watched as Caster's face fell. He looked exactly the same as Regulus had done in his first year at Hogwarts when he had tried to talk to Sirius and his friends and Sirius had ridiculed him and told him to get lost.

"What do you mean?" Caster asked in a small voice.

"Sirius is your uncle."

Caster nodded, slowly taking in the information, struggling to keep control. "Ok, then where's my father? Can I meet him?"

"No, your father's dead…. Caster!"

But Caster had already run off. Both Leo and Christine went to follow him but when they reached the door they had to stop, realising that only one of them could go.

"Are you going?" Christine and Leo asked at the same time. They then exchanged uncomfortable looks.

"Maybe we should give him time to think?" Leo finally said.

"Do you think he'll be all right?"

"I think you have a lot of explaining to do. I mean, I always thought we were, you know, brothers- real brothers and you always told us that Dad was dead,"

"Regulus is dead."

"Regulus?"

"My brother," Sirius explained.

"Caster's dad," added Christine.

"That's just…. Isn't that illegal?"

"No," both Sirius and Christine said at once.

"It's just… a little unusual and a bit confusing," Sirius added. He wished that he could leave Christine to explain everything. He had only been talking to Leo for a few hours but still, he didn't feel like a father. Leo was just a teenager that he had just met. He didn't know what to say to him.

It wasn't like with Harry, with Harry he had something in common with him. Harry was James' son and they both loved talking about James and Sirius had known him- really known him before he was imprisoned. He had been desperate to see Harry, to learn anything he could of him- the connection had always been there.

It wasn't like with Caster either. He didn't know Caster but from the moment he had first seen him he felt connected to him. He was so like Regulus. Caster was like his opportunity to make peace with his brother. Make up for everything that he had done wrong. He felt indebted to both James and Regulus and their sons needed watching over so that was how he's make amends. But Leo… Leo was the result of a malicious attack at an enemy. How could Sirius ever feel connected to him?