"The past meets charm is a nice little spell designed to transport the casters to the first time they ever met, or at least where in a close proximity to each other. It's mainly used with an invisibility potion, or for those lucky enough with an invisibility cloak and used for nostalgic purposes or to remind people of a situation." Professor Flitwick stood on his usual pile of books as he gave his monologue on the charm, it was one of those queer bits at the end of a term which didn't actually seem to fit with the course. A very random thing to learn but easy enough to teach in one lesson.
"Now, quite simple, the people who want to recount their first meeting simply all mutter the incantation 'hetrotemps primiere' at the same time, some find it easier to make physical contact during the charm although in all honesty it's rarely needed. We will be looking for volunteers, as we have no potion I recommended people who met after discovering about magic, preferably when in Hogworts. To return your earlier selves need to say the incantation 'returnus'. Contrary to popular belief it is very rare that anything nasty occurs with time travel if you meet a past self, just a little confusion. When using a time turner this is different, part of the magic is bound in the mystery. So, would anyone like to try."
Harry knew that Hermione's hand would automatically shoot in the air, and then it would be him and Ron accompanying her on the little mission. It could actually be quite odd suddenly appearing in the carriage on the Hogworts Express. Harry didn't understand how this charm didn't screw up the time lines but obviously it had been tried and tested to make it onto the Hogworts curriculum, maybe it had a built in memory charm.
"Oh, Miss Granger. Come to the front of the class with whoever you want to go with." Hermione grabbed Harry's and Ron's wrists, one in each hand and they descended the tiered classroom. Harry heard Ron whisper in his ear "Trust her roping us in". Harry couldn't help but laugh, getting him a stern look from Hermione. Harry wasn't having a dig at her, just some of the stuff he'd dragged her through this was absolutely nothing in comparison.
Professor Flitwick's squeaky voice could once again be heard over the class, "Now remember, try and avoid direct contact with your past selves, but don't worry if it happens. To get them to say the incantation most people favour writing it on a piece of paper and getting them to say it. I must ask, you are sure that you three first met after finding out about magic, if the person has no memory of magic you are stuck there until you can teach them a few basic spells and get them to believe in magic."
"I am sure sir, we live miles apart and I didn't have any contact with the magical world until I got my letter anyway. We will be fine." Hermione said, in her usual know-it-all tone.
The three teens gripped their wands in the way shown. The wand required no movement but supposedly helped channel the magic.
"Ok then, on the count of three, heterotemps primiere. One, two, three"