Harry at a potions conference

[effazin]

Harry goes to a potion conference somewhere outside of Britain with Snape. He is registered as Snape's apprentice (as an excuse for him to be allowed to attend the conference). Snape enters some sort of contest/competition--to prepare brand-new potions under a time limit I believe, highlighting innovation and research. Harry is assigned to prepare ingredients and start a potion for Snape. Determined not to disgrace Snape (who is supposedly training Harry in potions), he does better/faster work than Snape expected, meaning Harry has to finish off a potion for Snape, because the potion he was supposed to be starting under Snape's supervision reaches a critical point in the process sooner than Snape expected, while Snape is occupied with another potion or another step that can't be interrupted, so Harry, having brewed the entire potion, is credited with the prize. Harry is upset about this, as he acknowledges that he made the potion only because of Snape's instructions, and tries to convince the conference directors to give Snape the prize instead.

I know this is just a chapter in what I think was a fairly lengthy story. It is a fairly old story.

Sorry--I can't seem to find tags that would fit what I remember.