I'm seeing Alchemy as minimum 8 issues... and possibly as much as 10 or 12.
This is a pretty ambitious story for me, and more layers of the story keep revealing themselves and demanding to be included.
This story is very much a culmination and climactic payoff of all of the other stories...
Especially Circle of Blood, Skin Deep, and Metamorphosis.
And also has some Scarab references in it.