The Crooked Spire is the 3rd in the John-the-carpenter series by Chris Nickson. It has dropped to $0.99 at Kindle and Kobo US (coupon/VIPable).
Kindle US:
https://www.amazon.com/Crooked-Spire...dp/B01M7M9RFS/
Kobo US:
https://www.kobo.com/us/en/ebook/crooked-spire-1