Pairing: Alfons Heiderich/Edward Elric
Setting: 1921, before Conqueror of Shamballa
Dedication: numi_nami , for reminding me to write EdHei.
Say A (part)+B+C=D (whole).
What I originally had in my head was: ?+?+C=?.
What I ended up with when typing it out was: A+B+?=???!!111
I figured it out, though. I swear.