In the cupboard, Harry strained to hear.

A chair scraped across the floor; he guessed that Lupin had sat down.

"Well?" Lupin prompted impatiently.

"I'm curious, why is this so important to you?" Snape asked. "It can't possibly matter after all these years."

"It matters."

"Fine," Snape said, his voice sounding annoyed. "Now, what makes you think I have the answers you want?"

"You know perfectly well why. Arabella Figg. When she first mentioned that she didn't trust you, I actually defended you." He sniffed angrily. "When she told me she didn't believe the confession you made to the Ministry had been entirely accurate, I reminded her that you were questioned under Veritaserum. When she told me that another confession contradicted yours, I actually. . ." He paused, trying to get his voice under control. "I told her I placed more trust in your words than the words of a proven Voldemort supporter."

There was a silence after he finished.

"Do you expect me to thank you for your confidence in me?"

"I don't expect anything," Lupin smirked. "Let me continue."

"By all means, go ahead," Snape said, sarcasm returning to his voice.

"I would have left it at that," Lupin continued, "but your own actions betrayed you. I don't know how you managed to oust her, when she was so intent on getting the Defense job, and when she had Albus' full support. You must have gone to a lot of trouble to drive her away."

"What makes you think I had anything to do with it?"

"Who else?" Lupin demanded, his voice rising. "Don't try to deny it. Your plan didn't work. I was already at Hogwarts, Albus had invited me during the summer. We thought it best if very few people knew that I was here."

Harry could almost feel Snape's scowl.

"She had been my teacher once, if you recall," Lupin continued, "so of course we spent time together. Especially since. . ."

"Spare me the details and get to the point," Snape interrupted.

"The point is," Lupin said, bristling, "after you drove her out I began to entertain the thought that she might have been on to something."

"Too much time on your hands, perhaps?"

Lupin ignored him.

"I pulled the old files. I compared the confessions. I found the discrepancy."

"Let me see if I. . ." Snape began, but Lupin interrupted him.

"Let me clarify. I don't believe that you lied."

"How kind of you," Snape smirked.

"I believe the fault lay with the Auror questioning you. He skipped past the names of Death Eaters who had already been apprehended, and apparently skipped over the name of his fellow Auror as well."

There was a short pause.

"If that is what you believe, then why are we here?"

"Because of the other confession. For obvious reasons, I can't go straight to the source. You are the next best thing," Lupin exhaled sharply, "and I want you to tell me everything."

There was such a long silence that Harry almost began to believe that he was alone in Snape's office. Snape's voice made him jump, hitting his elbow painfully on a shelf corner. He just barely managed to stifle a yelp.

"Alright. But there is not much to tell."

"Tell me anyway, and let me be the judge of that."

"She had no intention of joining Voldemort. She came to our meeting place one time only, and it was to see me," Snape paused. "But you already knew that."

"Yes," Lupin confirmed. "I want to hear what her business with you was."

"I'm afraid that is a private matter."

Lupin snorted.

"And is of no importance," Snape continued, interrupting him before he could say anything. "She left, and never returned. There. Now you have the truth, and you can stop questioning her loyalty." He laughed harshly. "I hope you will not be losing any more sleep over this matter," he said in his most sarcastic tone.

In the cupboard, Harry sighed with relief and leaned his forehead to the cool stone wall. His mother had been innocent.

"Wait," Lupin stopped Snape, who had gotten up from his chair. "We are not finished."

"What more do you want?" Snape demanded, his temper rising.

"What was the date?"

"The date?" Snape repeated. "Do you expect me to remember? She came in the dead of night, and left before dawn. It was not important enough to commit to memory."

"Is that so?" Lupin demanded. "I happen to know the exact date. James was here at Hogwarts, and it was the one night that he was able to go home. He was looking forward to seeing her, they had been apart for more than three weeks. But he came home to an empty house. He waited, but there was a meeting the following morning and he was forced to return. After that. . ."

"Then why did you ask me, if you knew?" Snape interrupted.

"You didn't let me finish!" Lupin's voice rose angrily. "After that, he was unable to go home again for over a month. I didn't know this. You are aware, of course, that I could not keep track of him during the times I was confined to the Shrieking Shack."

"Yes, I am aware of that," Snape sneered.

"I had to go to Sirius for this information."

"Now there is a reliable source," Snape sniffed. "I suppose I should have known you would drag him into this one way or the other."

"Sirius was at James' side the entire time. He knows for a fact that James never left Hogwarts, and that Lily remained at home."

"What is your point?"

"My point is," Lupin said sharply, "that Lily and James were apart for over eight weeks."

"How sad for the newlyweds. Must have been hard."

Harry heard Lupin's chair scrape across the floor and hit the wall. Lupin banged his fists down on Snape's desk, hard enough to shake the walls and cause a shower of dried leaves and moss to fall from a topmost shelf inside the cupboard.

"Don't pretend you don't know where I'm going with this, Severus," Lupin's voice was strained, as if it took all his strength to control his anger.

"I'm afraid I don't," Snape told him, but his voice too sounded strained.

Lupin's voice dropped, Harry had to press his ear to the door to hear him.

"Don't. Just don't. Most wizards have trouble with even simple logic. Even Albus. And James. But not you. No. And not me either."

Snape didn't reply, or if he did, Harry could not hear it. After a moment Lupin continued.

"Their child could not have been conceived before James left. It is not necessary to have medi-training to know that it is not possible."

Lupin stopped, and waited. Snape stayed silent. In the cupboard, Harry pressed his ear harder against the door, his heart pounding so hard that in the silence it sounded like the beat of a drum.

"But. . . when. . . James came back. . ." Lupin continued, his voice strained and faltering, ". . . she announced the pregnancy. She said. . . that she waited until things calmed down, because she knew it would be an additional anxiety for James, something more for him to worry about. But now we know. . ." Lupin's voice trailed off.

"You're wrong," Snape said, and he laughed a short, shaky laugh.

"Am I?" Lupin demanded. "I don't think so! You must have known. Something like this would not have escaped your notice. You would have figured it out, just like I would have, had I had all the information."

Another chair scraped the floor, this time it was Snape who got up. He seemed to be pacing around the room.

"It isn't true. I saw him! And look at him now! That's James' son, no matter what you say. They must have. . ."

"No," Lupin said shortly.

The pacing stopped somewhere near Harry's hiding place. He could hear Snape's breathing, fast and labored.

"Think about it," Lupin said, his voice low again. "She was so good at charms. If she wanted to protect her secret. . . Didn't you consider the possibility?"

Snape didn't answer him.

"You did, didn't you?" Lupin demanded. "And you dismissed it based on outward appearance? I don't believe that you would accept that as valid evidence. . ." His voice trailed off.

"You confirmed it," he finally said.

Silence from Snape.

"You knew all this time. You left him with those Muggles even though you knew."

No answer.

"Look at me!" Lupin snarled, his heavy footsteps crossing the room rapidly. "It's over! You will not convince me that you were ignorant, and you will not convince me that I'm wrong! Stop trying. It's over!"

Lupin stopped, panting hard, out of breath and overcome with emotion.

"It was too late," Snape's voice was forced and low.

"Too late?"

"I saw him, right after. . . And I accepted at the time that he was James' child. When I began to have doubts, I. . . I tested him."

"And?" Lupin prompted, when Snape didn't continue.

"And it was too late. It was two years before he arrived at Hogwarts. Already, everyone was holding their breath, waiting to see if he would be accepted to the school, waiting for his reentry into the Wizarding World."

"So you did nothing? You didn't go to Albus?"

"No."

"Then he doesn't know?"

"No," Snape turned on him, and suddenly his voice regained its usual cold composure, "and you will not tell him. You will tell no one about this conversation."

"What about Harry?"

"What about him?"

"He is your son."

In the cupboard, Harry bit his lip until it bled, a desperate attempt to keep back the howl of anger and pain that had been welling up in his chest.