Modifying Harry (гет)

After the disastrous idea taking the Flying Ford Anglia after Ron and Harry missed the Hogwarts Express, Harry has to go to the hospital wing to make sure, that he hasn't seriously gotten hurt. Instead of Madam Pomfrey however, Harry finds Professor Snape.
While annoyed at having Snape, of all people, doing his preliminary health inspections, there's nothing Harry can do but keep his temper in check to get away sooner rather than later.
Snape, however, had found a rather interesting little spell over the summer. Soon, Harry found his reality rather different to what it had been just a day ago. Not that he knew.