Chapter Text
The first time is like being struck by lightning. It hits fast and hard and slips through his body like a vicious current; burning him from the inside out and leaving him screaming until his throat is a raw, sore mess that refuses to take in food without pain for weeks afterwards. There is a rushing in his ears when it happens, like a raging river that crashes into him and tries to drown him in itself. Bright colors splotch behind his eyelids but he barely notices them, too concerned with the agony of the experience. He never hears or sees his relatives run in and stare at him in horror, never views their worried and panicked faces. He only learns of it later, when their behavior changes, when Dudley reveals the details to him in a quiet voice full of worry.
He thought he’d followed the instructions in the animagus book perfectly, but clearly some mistake was made, because this pain is nothing like what the book described. Eventually it passes, snapping away as quickly as it had unleashed itself upon him. The next morning when he can see without his glasses and the mirror reveals minor changes he will panic and try to find an explanation in the book; and he’ll discover the incredible mistake he has made.
The second time is more like lava. The pain comes slowly, torturously, moving through him bit by bit and making him gasp and whine and cry. It is both better and worse than the first time. The pain is not as intense as then, but it lasts for hours . When it’s finally done, it will be many hours more before he moves; movement that comes only because Dudley carries him to his bed and washes the vomit he never realized he expelled from his body with a wet rag. When he can move again, smells will have become stronger, nearly tangible things in the air around him. The mirror this time will show pointed ears and two strange bumps on his forehead.
The third time is better. His relatives, afraid for him more than of him (and who would have thought they cared enough for it), are with him in the living room when he gasps and his face contorts in pain. It’s not as bad as the first two times, and he likens it to getting too close to a fire and feeling the heat of the flames along his body. He staggers from his seat and Vernon helps him into bed this time so he might at least get some sleep when it passes.
They have been far kinder to him since he saved Dudley from the dementors. Part of him rages that it should take something such as that to earn this care from them. Part of him cries that he should have been good enough for their kindness from the start, when he was still young enough to yearn for it. Most of him is too tired to do much more than accept it.
The flames of pain lick across his spine and his face, and he falls into an exhaustion-induced sleep before they fade. It is when Petunia gasps in shock the next day and a rush to the mirror reveals the scales that he finally decides it might be time to owl Sirius. He’d resigned himself to dealing with the consequences of his actions alone, but this is beyond what he can handle without help.
He can’t remember the last time he asked an adult for help, too used to being disappointed.
There are no larger 'fits' for some time, just smaller occurrences such as being so itchy in a single place until his scratching peels away bloody skin to reveal more scales. There are headaches, and the time when his fingers feel as though he has dipped them in hot candle wax. Each instance is accompanied by more and more changes, and Sirius' reply to his letter reveals very little the man can do to help, and no knowledge as to what is happening to him.
There is peace for a time, long enough to make him feel that perhaps whatever is happening has finally stopped. The Dursleys are relieved, and help him try to hide the current changes enough that he can run in disguise to Diagon Alley and try to find more books on the subject of animagus transformations gone wrong. He finds very little to help him, and doesn't dare contact Hermione for help. Then the last fit comes.
Like the first, it tears screams from his throat and he is left unaware of the world around him until he is claimed by sleep. This time is like molten steel being poured down the length of his back, and it is the worst of them. When next he is aware enough to take in the changes wrought upon his body he barely feels afraid of it all, having nearly expected it. He wonders if it is done now, and begins to try to shift into another form, sneaking into the woods nearby to practice. If he must bear with these changes then he wants at least the benefit of a proper transformation; some silver lining to come alongside the horror. He doesn’t manage at first, but one day his bones shift beneath his skin and he falls to all fours and grows and grows and grows . A lake reveals his appearance to him and he owls Sirius again to describe what he has the power to become.
The man comes to get him then, hiding him away in Grimmauld place's attic without the Order's knowledge. They hunt through book after book until they find the creature that he is. When they do, they set their minds to finding the best way to hide it. No one can know. No one can see. Through plan after plan and glamour after charm after complex runic configuration they manage to make him look as he once did to anyone else's eyes. Only Sirius and he know the truth, not even Ron or Hermione will be told, and that, Harry decides, is for the best.
He loves his friends, but he will not bring this burden to bear upon them.
He can’t .