The Owlery was almost deserted. Most of its nocturnal inhabitants were out hunting their suppers of mokes, voles and mice or, in Pigwidgeon’s case, beetles. Only three pairs of round, black eyes witnessed the arrival of Harry and Malfoy. A dark, spangled Long-eared Owl raised his ear tufts in sudden fright, but then relaxed, uttering a low, apologetic coo. Hedwig’s perch was empty.

The boys crossed the tower, crunching over a carpet of dark pellets, crushing the desiccated fragments of bone, teeth, fur and feathers underfoot. They didn’t expect anyone to be wanting to send an owl at that time of night, but it was just as well to be out of sight of the door. Three heart-shaped white faces swivelled silently, tracking their progress.

“So, only the questions we discussed, OK?” insisted Harry.

“Absolutely! You have my word as a Malfoy!” Draco replied, exaggeratedly pompous.

Harry could hardly believe that he was here, in the Owlery after curfew, scheming with his former arch-enemy. It was straining credibility too far to think that Malfoy might also possess a sense of humour. But the Slytherin was grinning. Harry unstoppered one glass phial and, using the tip of a quill as a pipette, squeezed four clear drops onto his tongue. The liquid burned in his mouth for a second then evaporated, leaving an unpleasant aftertaste of aniseed, menthol and something else bitter, ancient and deep.

“Are you ready?” Draco whispered.

Harry nodded.

“Right-oh. Question One: do you hate Professor Snape?”

“Yes.” Unequivocally. The word left Harry’s mouth automatically; he felt like a puppet or a ventriloquist’s dummy, with no control over his own speech.

“Question Two: Why do you hate Professor Snape?”

“Because he raped my mother.” That was the truth. Not necessarily the whole truth, but it seemed to satisfy the serum.

“Question Three: what are you going to do to Professor Snape?”

“Kill him.”

“How?”

“I am going to turn him in to Lord Voldemort.”

Malfoy pursed his lips. He had refused to believe it when Harry had first told him that Snape was a double-agent, that he had been spying for Dumbledore for over fifteen years, that he had contributed to Lucius’ arrest. But there was no doubt now that Potter was telling the truth.

“Question Five: do you intend to join the Dark Lord?”

Harry hesitated; he couldn’t pretend that the idea had not crossed his mind.

“I don’t know. I might. I just don’t know,” he said quietly.

“Honest but inconclusive,” Draco commented. “Now then, Question Six: do you, or do you not, have a ‘thing’ for Hermione Granger?”

“Hey! That’s not on the list! That’s not fair!” Harry protested, but even he was curious as to how he would answer. He heard himself saying:

“I love Hermione. But not in that way. She’s a friend. She’s really important to me.”

Malfoy had the grace to be embarrassed.

“Sorry, Potter. Simply couldn’t resist. Didn’t mean to get heavy, though. Here, you’d better have the antidote…”

Malfoy knew about James’ letter and the fact that James had put Harry under an Honour Obligation to take revenge on Snape. The only thing he did not know was that Snape was Harry’s biological father. Harry had explained the details of his plan and Draco, still smarting at Snape’s betrayal, had willingly agreed to become an accomplice.

He would give Harry advance notice of the time and location of the next Death Eater meeting.

The timing couldn’t have been better. On the Thursday morning almost a week after their conversation in the Owlery, Draco sidled up to Harry after breakfast as he was leaving the Great Hall.

“It’s tonight. Are we still on?” He hurriedly gave Harry the details.

On Thursday afternoons they had double Potions. It gave Harry the perfect opportunity to play his last solo scene before the Grand Finale.

Now that the day had finally come, Harry felt surprisingly calm. He returned to his room and took his father’s letter out of his inner pocket. It was creased and dog-eared, the parchment softened by many readings, foldings and prolonged contact with his body. He read it again, perhaps for the last time.

“James, I am your son. I will be worthy.” he said out loud. He hid the letter in a drawer, securing it with a Locking Charm. There was a distinct jauntiness in his stride that morning as he strolled to Transfiguration.

It was a miserable afternoon. Even with seven cauldrons simmering, the dungeon was still as icy as a morgue. Harry’s fingers were white and numb as he crushed porphyry crystals to a paste in his mortar with slices of Loach liver. He couldn’t remember if he had added two drops of Ptarmigan spittle or not. He didn’t care: it was unlikely that Snape would ever get to mark this particular potion. Harry waited, choosing his moment. He sensed that Draco, beside him at the desk but working independently at his cauldron, was also waiting and watching, acutely conscious of his every move.

Behind him he could hear Snape’s carping comments as he glided from student to student, criticising their progress and distributing the final ingredient.

“Mr. Brocklehurst, if your nose drips into that cauldron the potion will be contaminated…

“No. It is absurd to suppose that an albino grouse is the equivalent…

“It should be self-evident, Miss Abbot, that the counter balm would require an inverted infusion…”

As Snape approached with the sprigs of Fluxmyrtle, Harry emitted a shriek of pain and collapsed over the desk, clutching his head.

“Stand up, boy!” Snape barked, and then, as Harry continued to writhe,

“Potter! What’s the matter?”

“It’s my scar, Sir. It hurts. It’s burning!”

Snape’s reaction was immediate and urgent. He forced Harry up and pushed him firmly into a sitting position.

“Look at me, Potter! Concentrate. Focus on your Occlumency. Look at me and focus.” He spoke clearly, authoritative, imperative.

Harry felt a flush of satisfaction as he saw anxiety plainly etched in the teacher’s dark eyes. He looked wildly at Snape and cried,

“He’s summoning me. I can feel it. It’s Voldemort - he’s calling me! Don’t let him take me, Sir!” Woah - don’t overdo it.

For once Snape did not reprimand him for saying the name.

“You must resist, Potter. Defend your mind. Concentrate,” he insisted.

Harry allowed himself to go limp.

“He’s gone, Sir,” he whispered.

“Do you need to go to the hospital wing?”

Harry shook his head, but remained slumped over the desk. For a second Snape seemed undecided, then he turned formally to Malfoy,

“Draco. Potter should rest. Accompany him to his room. Return promptly.”

In the corridor Harry winked at Malfoy.

“Did you see that?” he crowed. “Putty in my hands!”

Draco viewed him with unconcealed admiration.

“That was one hell of an act. You even had me fooled! I liked the ‘Don’t let him take me, Sir’ bit. That was classic.”

“I thought that was getting a tad OTT, myself,” laughed Harry.

“Frankly, Harry, the whole thing is OTT.” Draco was suddenly serious. “Didn’t it ever occur to you to do something simple like poisoning his Firewhisky? For Merlin’s sake, Harry, Snape’s going to be called to the Death Eater meeting anyway, whether you lure him there or not. If you think about it, your entire plan is excessive - it’s steeped in melodrama. It’s like it’s a game to you. You’re actually enjoying it! For a Gryffindor, you’re really quite evil!”

“Is that a complement?” Harry was on too much of a high to be offended. He knew Draco was right - in plotting his revenge he had indulged his taste for the dramatic. An element of ostentation had seemed somehow in keeping with the macabre Gothic-romantic-Eastern rites of the Natqah revenge ritual. A dose of Streeler Venom would have been banal by comparison. Harry felt he owed it to James to exact the revenge in a style befitting the high-flown tone of the letter. There was an attractive natural justice in causing the ‘Dark Lord’ to be the instrument of Snape’s destruction.