William was walking by the statues on the fifth floor when he decided he should probably check on how his egg Mischievous was doing. He took the egg out of his pocket and saw that it was a bit dry, so he put it down on the ground for a moment in order to get his wand out. To his surprise and dismay, he saw that Mischievous was trying to skip towards the statues. That was when William realized that he hadn't named his egg Mischievous for nothing, it apparently a very strong bond with the Weasley twins and wanted to be near the portable swamp, for some crazy reason. Either that, or Mischievous was trying to find its own way of becoming moisturized.

William brought his wand out of his pocket and called out Accio, which caused Mischievous to stop and come towards him. He grabbed the egg and saw that it was really dry, even drier than a few moments ago, so his suspicions had been right. The egg instinctively wanted to go into that swamp, which would have been really bad! "Argentum Humidus", William said, twirling and pointing his wand at Mischievous at the same time he said the incantation.

William checked and saw that the egg was no longer so dry,so he knew that it would be okay. He pointed his wand at the egg one more time and said "Excolo", making a tracing motion all over to make sure it was free from dirt and anything that might cause rust. Mischievous was finally clean.

"Now let's get you out of here before someone sees you and tries to eat you for breakfast," William whispered to the egg, placing it into his pocket once again.