Harry and Cedric disappeared after grabbing the triwizard cup. Different from canon, they both never returned. Turns out they somehow ended up tumbling through time ending up a couple years before the fall of Egyptian rule. Cedric unfortunately dies. The pharaoh sees his appearance as an act of the gods and claims him as his son. When the Alexander comes for Egypt the Pharaoh has his magicians hide Harry in what was going to be his tomb and place a stasis spell over him with the intention of waking him again once they drove the Greeks out. Millennia pass and Fleur Delacour is part of a small band of curse breakers from Gringotts London branch looting Egyptian graves. One of her asshole coworkers, fuming from her rejection, decides to get payback by tripping her such that she falls and kisses the mummy they’ve unearthed. None of them expected it to start breathing when she pulled her lips away.
“Harry?”
“Fleur?”
Drama unfolds when they realize everything found in the tomb under international wizarding law is property of Gringotts. Fleur decides to forgo her split of the profits in place of ownership of Harry (it’s partially a completion of the life debt her sister has as well)