Quicksilver Bonus Content
UPDATE from Callie Hart's newsletter:
"I know many of you have been waiting patiently for the extra Kingfisher POV chapters since the book's release, and I can confirm that a chapter will be going out every Tuesday for the next 3 weeks, starting on September 17th."
Also! Her newsletter said that Quicksilver is being traditionally published! Foil special editions are being made.