Book 4 of Defiance of the Fall is now out on Amazon, Kindle Unlimited, and as an Audiobook over at Audible. Proofed, edited, and generally fixed up. So if you're in the mood for a re-read/listen, be sure to check it out! As usual, this also means the older books are on sale for the next few days (US only, I think), where you can pick them up for just 0.99 apiece!
Book 4 covers the Underworld, the Base Town, and the first half of the Tower of Eternity, so plenty of fights and progress to be had. You can find links to the audiobook and ebook in author notes.