I'm torn on this. On one hand I wish there would be a sequel, on the other hand, I like the way it ends. Sometimes stories/scenes like this should be just left alone and the readers should use their imaginations to come up with a future.
In that light, you could use this chapter as a challenge - have other writers come up with a future based upon this event.
In any case, I did enjoy this tidbit. I didn't catch the potions switch although it does make sense.
One thing though - would Hermione really be this devious and underhanded?
If I pre-read this chapter, I probably would have suggested a minor slip by Hermione, perhaps a "non-Tonkism" or something like that. I wouldn't/shouldn't be a major thing, but just a minor clue that things aren't what they seem (and Harry, who was so into the moment, wouldn't catch it either.)
If you do feel compelled to put out a more on this, I suggest both a prequel and a sequel. The prequel would be just Tonks and Hermione, where the younger girl tells about her break-up with Ron. The sequel would focus on the impact of what just happened. I can see Harry being both happy and upset - happy knowing that Hermione feels the way she does towards him, yet upset that she resorted to subterfuge.
Anyway, this was good and rather than saying "I want more of this", I'll say, "You got any more half baked ideas?"
Author's response
I had planned on leaving this a one-shot, but a few people have asked for a second page. If so, it will be a very short one. I do better with one shots than with chaptered fics. Kinda like being a still photographer rather than a videographer. You have to get the entire story into one frame.
Yes, I do believe she is. In canon, who was it who suggested the use of Polyjuice, despite that they'd be breaking about fifty school rules, who stayed up with Harry until all hours to help him learn the things that would help him survive the TWT, and who kidnapped and blackmailed Rita Skeeter into behaving, and later writing a story she wanted written? Yeah. Hermione definitely has a sneaky, underhanded side to her.
I have a few ideas for your suggested pre/sequel, though I'll combine them into a short one-page. It will probably include all of your suggestions in one form or another.
I have plenty of biscuits bakin'
Thank you for your insightful words, and I'm glad you enjoyed the story.
Alorkin