Fear and Triumph
The three of them are gone again, off on some adventure to which he will never be privy. Actually, that's not quite true. In a few hours they will come tumbling through the portrait hole, each breathless in their own fashion. Sirius will be clutching his sides, laughing to the point of tears. James will be nursing some unfortunate injury, wincing and panting yet still with an air of triumph. Remus will trudge in last, wearing that pinched, pained expression he always gets. (He doesn't like to break the rules; it makes him squirm, but Peter will still see the gleam of delight in his tired eyes.)
They will feed him the story piecemeal, with James narrating but Sirius getting excited so that his voice bubbles over James'. Remus will stay mostly quiet, but occasionally he'll interject with some caustic comment that is nonetheless full of affection.
None of them will notice the throb of hurt that crosses Peter's face, because they won't look. He'll smile and congratulate them on a glorious escapade, but each episode leaves him cringing on the inside. But he'll only nurse his wounds later, long after the others have collapsed into bed and he's scurrying through the dark tunnels in the walls, too consumed by the rat-fear to feel the sting of their slights.
He doesn't understand why they don't think to invite him. He's not overly fond of James' and Sirius' mad schemes, but then neither is Remus, and he always gets dragged along, even when he protests. Peter is not brave or witty or dashing, but he simultaneously craves and fears the strange exploits of his more courageous companions. He yearns for it in a way that Remus doesn't, for Remus is too self-contained even though he doesn't know it.
For a while, he had equated himself to Remus. Both of them were shy, awkward, and—in their different ways—painfully eager to please. But now Remus outshines him. Though he lacks the charisma and daring of the other two Marauders, something akin to their spirit lurks within him. It's hidden, beaten down by the relentless moon, but some indestructible fiber lies coiled in his stomach, wound around his skeleton.
Peter has no such thing. He's just a sack of ordinary blood and bone and muscle and skin, one that hasn't quite lost its "baby fat," as his dreadful old aunts like to say. He sweats through his potion-making and stammers through Transfiguration reports and even in his fleeting moments of glory when he's scurrying-hurrying among the roots of the Willow, he still feels the gnawing, ceaseless fear.
He tries to enjoy it, to bask in those moments like Remus does, filing them away with exaggerated care for the days when the dark thoughts come, insidious and immovable. But Peter just can't do it—there's always the fear, lurking just beneath the surface, skittering away from the dazzling light that is James Potter but slinking forth again as soon as his idol has gone.
* * *
It is not his fear that will be his undoing, even though it is that which sets him on his hideous, twisted path. In the years to come, he will feel the fear rising, swelling. Soon he will no longer be able to maintain his desperate paddling and he'll have no choice but to beach himself or drown.
It's not the fear that destroys Wormtail as he scurries to the Dark Lord, flush with the secrets of his oldest friend. It's not the fear but the triumph, the inexplicable surge of vicious giddiness that seeps from his head to his toes. At last he has proved himself stronger than any of them ever dreamed, though they will doubtless perceive it as weakness. It takes every ounce of steel Peter Pettigrew never had to let that information drop from his stuttering mouth, and several more to force down the accompanying wave of guilt.
He finds the fear is useful now. He rocks back and forth in the dark, blotting out the gut-wrenching agony of his betrayal with the all-consuming terror. He cloaks himself in it, lives it, breathes it. It is so, so easy to sink into the rat mind, stunned by a deluge of panic and fright. He no longer has to think upon his crimes, his dashed hopes, his pain, at least until Remus pulls him from the blissful maelstrom.
* * *
For one final time in his life, Peter Pettigrew will conquer his fear. He will spare a life, paying homage at last to the ones he stole long ago, defying the Dark Lord and rising to meet his shame head-on. His final moment of triumph will crash upon him, and when at last death comes calling, the herald will be his own hand.