Chapter 138: The Werewolf's Lesson

Edward returned to Lupin's classroom after Dumbledore's silver reply told him to remain with a professor. The linked alert token stayed warm inside his pocket. Harry and Hermione were still there. Lupin had moved the desks away from the windows and kept his empty Wolfsbane bottle beside the staff message, proof that he had taken the final dose. 

Before the token could display another update, Ron stumbled through the door. Blood marked two small bites on his forearm. 

"Scabbers is gone," he gasped. "He bit me, knocked over the prefect's lamp, and ran across the entrance hall. I followed until the front steps." 

Lupin closed the door behind him. "Sit down. Hermione, bind the wound." 

"Peter is heading toward the Whomping Willow," Edward said. Red letters across the token showed that the tracked name had crossed the lawn and was moving beneath the tree's outer branches. 

Harry was beside him before Lupin could object. "That passage leads to Sirius." 

The mirror on Lupin's desk brightened. Dumbledore's voice came through it, clipped by movement. McGonagall and Snape were crossing the grounds. Sirius had been asked to cover the Shrieking Shack exit in his dog form, but he was not to engage unless Peter threatened someone. 

"All students remain in the classroom," Dumbledore said. "Professor Lupin, ward the door and wait for relief." 

The instruction ended beneath a crash from the corridor. A suit of armour struck the floor outside, followed by the fading squeal of a rat. The route on Edward's token changed. Peter had doubled back through a service stair before turning toward the grounds again. 

Harry reached the door first. 

"Stop," Lupin ordered. 

Harry opened it anyway. Ron shouted after him and followed. Hermione went to bring both boys back. Edward sent another alert through the token before running after them. He knew pursuit violated the plan; allowing three students to disappear without a professor would not repair that violation. 

Lupin overtook them at the entrance hall. "Behind me, all of you. We reach the nearest staff patrol, not the passage." 

A silver message from Dumbledore reported McGonagall approaching from the greenhouses and Snape from the west court, but Peter had already reached the Willow. The token showed his tracked name slipping beneath the roots and beyond its monitored boundary. 

Harry did not slow. "If he reaches Sirius, one of them will kill the other." 

"Sirius knows the condition," Edward said. "Running into the passage gives Peter more people to use." 

The Whomping Willow answered their approach with a sweep of branches. Lupin stunned the nearest limb long enough to strike the knot at the base. The opening under the roots became visible. 

A red flare rose behind them. Snape had seen their route. 

Lupin looked up. The clouds were breaking around the full moon. He had taken Wolfsbane, but the transformation would still occur and the Potion did not guarantee perfect judgment under stress. 

"I cannot enter that tunnel with you," he said. "We wait here for Snape." 

A human cry came from below, followed by Sirius's bark and the crack of a spell. Harry ducked under the root before anyone caught his sleeve. Ron went after him. Hermione swore and followed. Edward marked the entrance with red sparks, then entered behind Lupin because separating again would leave the younger group without anyone who knew the plan. 

The passage forced them into a crouch. At its far end, Sirius had Peter pinned against the floor of the Shrieking Shack. Sirius remained a black dog. One paw held the rat's tail while his body blocked the outer doorway. Peter changed shape in panic, becoming a short, balding man in torn robes. 

A stolen wand fell from Peter's sleeve. Harry kicked it away. Hermione summoned it into her hand and sealed it inside her bag. 

"You betrayed them," Harry said. 

Peter's eyes moved across every exit. "Sirius has confused you. He always hated me. Ask Remus. Ask anyone." 

"You will answer before witnesses," Edward said. "The Ministry has been notified." 

Peter lunged for Ron instead. Sirius struck him sideways in dog form before he could reach the boy. Lupin cast binding ropes, but moonlight entered through the broken roof at the same instant. 

His wand fell. He backed toward the wall, breath breaking as his bones changed. The Potion preserved recognition in his eyes, yet pain made precise control impossible. 

"Away from me," he forced out. 

Sirius released Peter and placed his dog form between Lupin and the students. He did not bite his friend. He used his weight to guide the transforming werewolf toward the empty yard, taking a slash across one shoulder when Lupin stumbled. 

Peter rolled beneath the broken table, changed into a rat, and fled through a gap in the boards. 

"No!" Ron shouted. 

Harry ran after the rat. Edward caught Ron's uninjured arm, but the boy pulled free. Hermione followed them to stop the pursuit. Edward sent a second flare and went after the three students, leaving Sirius to keep Lupin away from the passage. 

Peter's tracked name crossed the yard and entered the forest. It moved too quickly for the students to reach, then disappeared from the token's range. Harry stopped at the first trees, chest heaving. 

"We lost him." 

"Then we return to the flare," Edward said. "Now." 

A howl answered from deeper in the wood. It was not Lupin's. The sound carried rage rather than pain, and it came from the path between them and the castle. 

Fenrir Greyback stepped from the trees in full werewolf form. Old burns marked one shoulder from the Hogsmeade fight. His clothes hung in strips, and blood darkened his muzzle. 

Edward moved in front of the others. "Back toward the Shack. Do not scatter." 

Hermione cast the first binding spell. Ropes caught Fenrir's ankle, slowed him for one stride, and tore apart. Harry and Ron raised Shield Charms together. The impact drove them backward but kept Fenrir's claws away. 

"Again," Edward said. 

The second shield formed unevenly. Fenrir struck its edge and split it. Harry reached inside his coat for the silver token. 

"Flame Serpent Guard!" 

A curved fire barrier opened between the werewolf and the students. It did not pursue or bite. The outward pulse checked Fenrir's charge and forced him to cover his burned shoulder. A dark line appeared across the silver token, showing that its single use was spent. 

"Move," Edward ordered. 

They retreated together. The barrier lasted only seconds. Fenrir broke through the fading flame and turned toward Harry. 

A cutting spell crossed the space between them and opened the old wound on Fenrir's shoulder. Snape stood at the edge of the yard, black robes torn by branches, wand already moving into the next curse. 

"Behind me," he said. 

Fenrir charged him. Snape raised three slowing barriers, but the werewolf shattered the first and forced through the second. Edward cast a fire wall low across the ground to turn Fenrir's approach away from the students. He kept the flame broad and shallow, leaving Snape a clear line of sight. 

From the Shack came Sirius's bark and the scrape of Lupin's claws against timber. Sirius had contained him, but not without injury. 

Snape fired a Stunning Spell. Fenrir twisted aside and sprang toward him. 

Edward tightened his grip on the walnut wand. The plan had failed, Peter had escaped, and four students were still within reach of a transformed killer. There would be time later to account for every broken order. 

For the next few seconds, survival came first.