The air was cooler underground, heavy with the scent of damp stone.
Cassius knelt briefly beside the smear of blood on the floor — faintly red, still fresh.
He rubbed his thumb through it, then examined the streak under the dim light of his wand.
One of them was hurt.
More likely both.
Blood patterns spoke of something shallow but wide — Devil's Snare lacerations and tears no doubt.
They'd fought it, panicked, and paid the price.
Amateurs, who dont even pay attention in class.
Cassius stood and carried on, silent and precise, his mind working several steps ahead.
Each chamber was a chessboard; he had simply learned the pattern years before anyone else.
The next room shimmered faintly with movement — the winged keys.
Cassius sighed at the sight.
Several lay broken across the ground, feathers scattered like frost.
Blood again.
Weasley's, most likely.
Potter would have been the one convinced to ride the broom afterall making Ron the slower of the two and most likely to be attach by the keys beyond the few pecking at harry as he raced around.
Walking across the room he stood next to the door using his wand like a stethescope to listen at what was happening beyond it.
The fatal chess game was still in progress but minutes later came a blood curdling scream, followed by silence.
A few moments later cassius acted, quickly casting Accio to acquire the needed key and stepping through the previously locked door.
The chess chamber stretched wide before him, lit only by the flickering torches of shattered pieces.
The board was chaos.
Marble dust and fragments still strewn about like someone had cleaned up in a hurry.
Ron Weasley lay against one of the walls — pale, unconscious, and cradling a broken arm.
His chest rose and fell in uneven bursts, blood seeping through his robes.
Cassius crouched beside him, eyes narrowing.
"Lucky," he said softly.
Seems even without having to protect two of his friends at once Ron still used a self-sacrificing move to win the game.
Giving him a once over before determining he'd live even if left alone.
That done, he rose to his full height and surveyed the board.
The pieces — black knights, bishops, and pawns — had reset themselves, awaiting another challenger. Their eyes glowed with that eerie magical intelligence, fixating on him.
Cassius twirled his wand once. "Checkmate."
The explosion was clean and immediate.
Bombarda Maxima.
The word tore through the room, and every opposing piece detonated into a hail of stone dust and shrapnel.
A rare win in a game of chess after only a single move.
The roar of the spell echoed down the corridor long after silence reclaimed it.
Cassius stepped forward through the settling dust, not even brushing the debris off his cloak.
"I don't play games that are already won," he murmured, and crossed into the next room.
The stench hit him first.
Blood.
Sweat.
Troll musk.
Three of them — the hulking silhouettes of mountain trolls, each nearly twice his height, their clubs raised and slick with what looked alarmingly like fresh blood.
Harry Potter stood before them, back against the wall.
His wand was gone, lying scattered across the floor, and his left arm hung limply — clearly broken.
He moved like a trapped animal, eyes wide, wild, defiant despite the hopelessness.
The first troll swung.
Cassius didn't even hesitate.
"Sectumsempra."
The word was almost a whisper, but the effect was cataclysmic.
Invisible blades of magic shredded through the air, ripping through the nearest troll with surgical precision.
Its body split open in a spray of dark, glistening blood before collapsing with a sound that made the floor shake.
The second and third followed right after not even being able to register the death of the first.
But Cassius couldnt risk the three recognizing him after months of being away and falling subserviently in line to obey, fear etched into their very beings after his weeks of combat training against them.
The chamber fell silent except for the dripping of troll blood onto stone.
Harry stared at him, eyes wide, trembling somewhere between awe and terror.
"C-Cassius? How—what—"
Cassius stepped past him, inspecting the trolls as though assessing a classroom assignment.
"You're welcome, Potter."
Harry stammered, "You—saved me?"
Cassius turned his gaze toward him, cold and unreadable.
"I'm here to save you," he said simply, though the tone carried an edge Harry didn't quite understand.
"Wha... What about Ron?" Harry sputtered out.
"He'll live, i called the teachers so he'll be in the hospital soon, cmon we've got places to be dont we?"
Cassius ushered him on injured as he was, Lacerations, scatched, even a few stab marks littered his body beyonf the broken arm hanging limply by his side.
The next chamber shimmered with magical flame — black on one side, purple on the other.
The table in the center bore the rows of potions, each bottle neatly labeled with deceptive simplicity.
Harry frowned. "How is anyone supposed to solve—"
"Its this one," Cassius interrupted, scanning the bottles, after having read the same note.
Seven bottle total, five are probably just bitter water that would knock you unconcious while telling you its fatal poison, one would send you back, somehow... and the last was a potion to protect you from the enchanted flame allowing you to cross.
Harry blinked. "You're sure?"
Cassius gave him a look that ended the conversation as he held out the uncorked bottle to him.
"Drink."
Harry obeyed, wincing as the cold potion rushed down his throat.
The flames on the doorway parted at his approach.
Cassius waited for a heartbeat, before pulling out an identical potion from his pocket, swallowing it and following close behind.
Reaching the door beyond in no time at all.
Harry hesitated. "Why are you doing this? You don't even like me."
Cassius's smile was small and distant.
"Because, Potter… some stories deserve to be witnessed, and i was asked to be here as an insurance policy."
Realizing Cassius wasnt here because he wanted to Harry stopped questioning him and reached for the door.