Disclaimer : I don't own Harry Potter.
Harry stared at the drinks in front of him with a contemplative glint in his eyes, and then at the waiting sitting Dursleys family behind him.
Last year, in the ministry, Harry had, somehow, successfully annihilate the feared Lord Voldemort after the death of his Godfather, Sirius Black. Dumbledore had speculated that it was the feeling of losing somebody that made Harry's magic leash out of control toward Bellatrix, and destroying the woman. In the process, he also destroyed the controller of the Mark the insane woman had. The old coot had also said that he thought the Dark Mark in some way worked almost the same as a slave Mark worked. Bonding the slave with its master.
The problem now was Harry still must spend his summer with the Dursleys. Dumbledore said that the blood ward was still working and because maybe there was some bad people (Death Eater) that wanted to kill him out of revenge, he must came back to the Little Whinging.
The worst thing, now that Sirius had died, the Dursleys almost as soon as he stepped into the house started making him work. He wouldn't be surprised if they planned on working him to death.
Luckily, Dumbledore had told him this right after they were alone, leaving Harry with some time to think and planning.
He pushed the thought of Sirius's death to the back of his mind at that time, focusing on to more important matter. He had no doubt that now Voldemort had died, the number of people protecting him at the Dursleys would be lowered. The Dursleys could kill him and the Order wouldn't know, especially if Mundungus was the one in shift. He needed to do something.
So he read some book in the library, restricted section, and found a potion that worked almost like Polyjuice did, only this particular potion worked only until an antidote was administered, worked two way, so almost like two people would switch bodies, only it wasn't a switch exactly, just changing the look s of the two people. And the potion could be brew under 2 hours, plus the antidote. Harry deliberately forgot the fact that the potion was dark.
Making the potion was easy, he wasn't a master in cooking only to fail in Potion. If not for the people who sabotaged his work in class, he would be the best in it. But he didn't want to bother himself by protecting his work. Snape wouldn't care if he was the bestest of the best in Potion, he would still got T. Why bother trying?
And now, he smirked, inserted the potion into one of the glass, specifically targeting the glass Dudley always chose. He put the drinks onto the table, smiling gleefully inside as he watched Dudley drank it. Now he only needed to wait until midnight to change place with Dudley, yes, getting into Dudley's room to haul the boy into his own dreadful room. It was very lucky that the potion would only work after four hours.
He would have much fun with the Dursleys this summer.