James comes home from work and scoops his son into his arms. "Hiya, Harry," he says, doing patticake for him. "Where's Mom?"

Lily comes out of the kitchen, covered in flour and snarling. "Where did I put that cake pan?"

"Wonderful wife! What's the occasion?"

She sends him a look. He grins and winks.

"Let me guess. Is it Daddy's birthday?"

Harry, sucking his thumb, shakes his head.

"Is it Mommy's birthday?"

Another shake.

"Is it Bazoo's birthday?"

Harry looks at his fish, thinks a moment, then shakes his head.

"Well I can't think of anyone else. Maybe Mommy thought it would be a nice surprise."

"It's Harry's birthday!" she says, wrestling him away from his father. "And we went to the park today and Harry walked all on his own!"

"What else did you do?" James crouches in front of his son, as Lily is now trying to demonstrate walking with a very wobbly Harry. "Frisbee? Tag?"

"We bought ice cream, didn't we, love?" Lily says to him. "And we chased the funny ducks…"

James had never told Lily that he knew, and Lily never brought it up. Once, cautiously, she asked after Sirius. She hadn't seen him since he had left that day; she tried to contact him a few times but he was gone. It crossed her mind that he might have left London.

On Harry's first birthday she opens the door and he is there. He looks grim and she, turning around, sees that James is also severe in his own way. He invites Sirius in, and now he is showing off his son and pretending it's like old times. Meanwhile his face is struggling to remain unreadable, flashing between love and pain and hatred.

Lily spends the time quietly. James thinks it is guilt but mostly she's annoyed. James sprang this on her when she wants more than ever for Harry to be happy. Her whole life is now centred on this hope: to forget and rebuild.

James has torn that down. He seemed to have been working with her, these past two years. There he stands, holding his son, facing his best friend, his face a happy mask, and she tries to understand. He has always worshipped her, she doesn't know why. He is pretending to have forgiven Sirius. And he is ruining Harry's birthday.

She watches him and waits for the explosion.