"Ah, there he is!" James exclaimed as Sirius stepped inside his and Lily's bedroom. Lily was holding the baby, clutching it to her chest while propped up against a huge mountain of pillows, and James was crouched beside her and tenderly stoking her hair. "Harry's first visitor! He's all cleaned up now and ready for the world to see."

Sirius froze beside the door. "Did you say Harry?" he asked. "Did you say he?"

"Yep," said Lily, smiling down at her baby. "It's a boy. Harry Potter, we're calling him."

"Harry Potter," Sirius murmured, turning the name over in his head. "I like it."

"You want to hold him?" James asked.

Sirius swallowed—the last time he'd held a baby was when his cousin Andy had brought her daughter to see him at Grimmauld Place. That felt like a thousand lifetimes ago. But this was James's son—of course he wanted to hold him. "I—all right."

He knelt down next to James and let Lily slide the baby into his arms. "Make sure you support the head," she warned. "Otherwise he could break his neck."

"Seriously?" Sirius made sure to hold the baby's head very firmly. Newborns were so fragile; he couldn't imagine how his mother had taken care of two of them. Had she ever cradled Sirius against her the way Lily had with Harry?

The baby was sleeping; a bit of drool escaped from his lips, which James wiped away with a small face-cloth. "He looks like you, Prongs," Sirius murmured.

"You think so?" James asked eagerly. Sirius nodded—he couldn't quite put his finger on it yet, but there was something in Harry's face that reminded him very much of his best friend.

Lily cleared her throat from among her nest of pillows. "Sirius," she said, "James and I had a favor we wanted to ask of you. A big one."

"Anything," he replied quickly, looking up.

Lily turned to James, smiling a little, and took his hand. "Well, the two of us have talked it over, and we…we wanted to know if you'd like to be Harry's godfather."

Sirius blinked. "I—wow. Of course, I'll be whatever you want me to be." He glanced between her and James. "But what would I need to do, exactly?" He didn't have godparents; he wasn't sure how any of it worked.

"I don't know, mate, just…help be a parent to him," James said. "And take care of him if something happens to me and Lils."

"Don't say that, James," Lily whispered.

"We're in the middle of a war," James pointed out; "we've no idea what's going to happen. I just want to know that he'll be okay no matter what—and I know he will be with Padfoot." James chewed on his lip. "Pads, you've got to promise you'll look after him if we can't."

Sirius peered down at the baby in his arms. He was so tiny, so helpless…. Sirius had no idea how to look after him. He never could have imagined he'd be here, still only twenty years old and reckless and stupid and being handed such a responsibility. He and James and Lily…they were all still kids themselves.

But Sirius would do anything for James, and the baby in his arms was his son, and that meant that Sirius would do anything for him, too. He could be a godfather or a father or whatever else little Harry Potter needed him to be. There was no question, not when it came to Prongs and his family.

"I promise," he told James and Lily, leaning down to brush a kiss against the baby's nose. "Whatever happens, he'll always be safe with me; I swear it."