Harry was just turning to go up the stairs to the girl's dormitory, when...
"It's not going to work, Harry," He looked around, to see Hermione Granger sitting in one of the arm chairs in the common room.
"It might this time," said Harry "I've made some adjustments. I'm definitely going to disprove you this time."
It was an improvement over last time. He got seven steps up the spiral staircase before they flattened into a slide and he slid back to the bottom. Hermione raised her eyebrow, a silent 'I told you so'.
"I don't get it, my formula was perfect," said Harry, scratching his head.
"Well, 'Harriet'," said Hermione, using a female name to emphasise the fact he was a girl "Do you think the Founders of Hogwarts would have overlooked a detail like that? They thought boys were less trustworthy than girls, and as long as you still believe you are male, you will not be able to walk up those stairs...."
Harry's head shot up, as Hermione realised exactly what he was thinking.
"No, absolutely no way, I refuse to do that, I won't do it, Harry," said Hermione, trying with all her might to convince her friend out of his scheme.
"It's just suggestion, Hermione," said Harry "Making me think I'm really a girl without actually becoming one completely."
"It's too risky, Harry," said Hermione "What if I mess up?" Harry raised his eyebrow "OK, but what if we get separated, or I get injured? What about your classes? What will you do about those if you're gallivanting around as a girl? What if, while you have the emotions of a girl, you fall for a guy?"
"You spend far too much time on that writing.com you told me about," said Harry
"What if the potion runs out before I change you back?" asked Hermione