I'd love there to be something like this, perhaps to raise money for St. Mungo's or rebuilding of Hogwarts, whatever. Snape and Harry must be paired, of course ;) And they fall in love over the course of the race and all the exotic locations they visit.
2) "People change in the Maze."
After the events in the graveyard, Harry has a very extensive medical exam from Madam Pomfrey, who discovers Harry is pregnant. Everyone thinks it was Voldemort or one of his Death Eaters, everyone except Snape who'd been at the graveyard that night and knows for a fact that the rape must have happened before Harry got there. Snape helps him come to terms with what happened, as he is the only one who believes the real story. But what was the real story? Who was it?
3)Historical AU
Harry is a young knight on crusade in the Holy Land and Severus is a Saracen leader/general. Harry is captured on the battlefield and taken as the newest addition to Severus' male harem. Being brought up very devout, Harry has no idea such things even existed. At first he angsts over the things Severus does to him, could have a bit of dub-con to start or Stockholm syndrome, where Harry falls in love with his captor. Happy ending preferred, but whatever the Muse wants ;)