Fic: Polyphony (chapter 4)

I've updated Polyphony with chapter 4, and it should, in theory, be done - but I think there's a final epilogue but we'll see when that happens!

Polyphony, ch4
c. 3700 words, M or E, ymmv, Erich/Biggles/Algy
They've had a lot of emotions, but what if they had more emotions only this time also sex.