Did we have linkage from Roger's books to whatever we need to know from Willow? Or is that essentially two separate plot threads, and the Willow part goes

Xander: How do you help a poisoned vampire? (Already asked)
Willow: I'm not sure, but the place to find rare ingredients would be Diagon Alley?

Do we need another e-mail in there in between, from Xander saying "We've found something that might be helpful: ________ - but have no idea where we can get it?"