Quotation question

[GulPlum]

Richelle Votaw wrote:

<big snippo>

> "Something tells me we're going to regret this."  
> anybody know where and in what context?  

Thank you, Richelle, for causing me to break my resolve not to touch 
my CoS book until after I'd seen the movie. :-)

I've just read 90% of it, and haven't seen that quote anywhere. It 
looks like it's a line added into the movie, and whilst there are 
plenty of things the kids might regret doing, I'd be prepared to bet 
that it's connected to preparing or taking the Polyjuice Potion. 

Anyone else?