“You did WHAT!� James yells at his friends.

There is a long silence, he can feel his heart thumping in his chest, and then Peter speaks, “Padfoot told Snivellus how to get in the Whomping Willow. It won’t matter though, will it?�

James balls his fists in rage. For a moment, he considers hitting Sirius but instead punches the door, splintering one of the panels.

“It’s not a big deal. For Merlin’s sake, he won’t do anything. Snivelly’s a bloody coward and you know it!� protests Sirius, but he won’t look James in the eye.

“And you’re sure about that, are you?� James retorts. He’s pulling his shoes on, but doesn’t bother with his cloak; the folds will only hold him up. “You’re willing to bet Remus’ future, and Snape’s life on your theory?�

“Remus’ future? What the hell’s that got to do with anything?� .

James shoots Sirius a bitter look and heads for the door. “You really don’t give a fuck about anyone except yourself and your own ball of misery, do you, Black?�

He doesn’t wait for a response, doesn’t even hear the door slamming behind him or the angry cries of his friend as he careens off the walls of the stairway in an attempt to stop this.

Rushing out of the Tower and down the rickety staircase, James glances out of window, only slightly heartened by the fact that it’s not quite moonrise yet. Perhaps if he’s quick enough he can get there before Snape touches the knot on the tree. Perhaps, he can get there before the sun disappears. However, it is a hopeless plea, for the orange skies of the sunset are fading fast into the blackening sky.

Perhaps, just this once, Remus won’t become the monster.

James runs, faster than he’s ever run, his thoughts outstripping his steps in this constant race.

Don’t be too late.

Don’t be too late.

Remus, fight this. Remus, fight this. We’re so close to helping you, only Peter to go now... Please ... just fight this.

For Merlin’s sake, Snivelly, just, for once, prove Sirius right and don’t turn up.

But he knows Snape is not a coward; he will come here tonight. And if he is killed - or at the very least cursed with lycanthropy - then Moony will live forever in Azkaban’s shadow.

James runs, his heart fit to burst, until he comes to the tree. He cannot see Snape, he cannot see any sign he’s been here, but something is wrong. Taking off his glasses, he blinks and rubs his eyes, and then he realises. The branches of the Whomping Willow aren’t moving. It’s possible that Madam Pomfrey has been lax for once and left the tunnel exposed, but he knows this is not the case.

Dumbledore could stop this, he thinks, looking back to the castle. But it’s too late to return. Without hesitating, James dives into the tunnel and runs, runs faster than before. He loathes Snape, and knows the enmity is mutual, but all the hatred in the world, all the need for revenge, does not make this right.

“Snape!� he calls desperately. “Are you here?�

James has been along this path many times, but has never run so hard. He is gasping for breath, gagging on the fetid air in the tunnel, and then he sees the Slytherin boy, his wand aloft. “Don’t!� he tries to shout, but his voice is weak from exhaustion. This can’t let this happen, or Moony’s worse than dead.

Snape hears his stumble and turns his head. He is smiling slightly, triumphant at last that he is about to discover Lupin’s secret.

A sliver of moonlight peeks out from the cracked door of the Shrieking Shack.

A low growl ascending to a terrifying howl echoes along the tunnel.

The wolf is awake and is snarling for its freedom, launching itself at the broken wooden door as it scents the prey it has always been denied.

James launches himself at Snape and pulls him back.

“We have to leave,� James shouts in Snape’s ear. He shakes him, but Snape has frozen. “Sni... Severus! We must get out! Come on!�

Pulling on his enemy’s arm, James drags him away and together they run back up the tunnel. Snape looks back and can see the beast, the terror in his eyes mirroring James’. It takes an age to run back, their backs bent along the narrow tunnel, both gasping for breath and grasping at life as they flee the horror within. They reach the safety of the open air and both collapse on the cold, damp grass, gulping gratefully at the fresh evening air.

“He’s a werewolf!� Snape rasps. “I knew it.�

James turns to look at Snape and sees a glint in the other boy’s eye. “You can’t tell anyone this. It will ruin his life.�

“Lupin could have killed me, and Black sent me there,� Snape replies coldly.

“And I saved you,� panted James. “You don’t have to like me, Snape, but you can’t tell anyone. I’m begging you.�

“Don’t say you did this for me,� Snape says, his voice a sibilant hiss. “I owe you nothing, Potter. You were trying to save Lupin’s hide, and Black’s skin. Why should I keep this secret?�

“Because I say you must,� says a voice from above them. James looks up into the face of his Headmaster. Usually he is benevolent, his eyes twinkling, even as he reprimands them for some mischief they have wrought throughout Hogwarts. But now, as he towers over them, James is struck with awed relief at the terrifying power of the man.

Everything will be fine now. Snape will not tell and things can go back to the way they were ... except...

They can’t be the same ... not ever.

Dumbledore is flanked by Sirius and Peter, both of whom look pale and frightened. James wonders who went to Dumbledore first. He desperately wants it to be Sirius, but for the first time ever, he realises his judgement concerning his very best friend is badly flawed. Sirius fears nothing - not even death - whereas Peter fears far too much, and that makes him the far safer bet.

Standing up he staggers, for he is weak now, the long run away from certain death exhausting him. But as Sirius catches his arm, James shakes him off and leans on Peter instead.