City of Miracles is the final book in the trilogy that starts with City of Stairs and continues with City of Blades, though it's set 13 years after the previous book in the series. As I get older, I find myself appreciating books which have grown-up characters at their heart, not just some pre-ordained teenager's quest and City of Miracles continues to give me what I want - what I've described to people as 'grumpy olds doing stuff'. Sure, there are teenagers here too but they're the supporting cast rather than the centre of things in a lot of ways.
The books are set in a world where miracles were once commonplace and the first book takes place in the direct aftermath of a war which has led to the death of the majority of the Divinities which once provided those miracles. The second and third books are about various things trying to fill the void left by those Divinities, either with a warrior class which had previously served them returning unexpectedly or with the offspring of said Divinities trying to claw their way to power.
The main character in City of Miracles is Sigrud, who also appears in the previous books, and who'd fled to self-imposed exile in the previous volume. As we meet him again, we discover he's been waiting for a sign he can return, which had never come, and now the person he'd expected to call him back has been killed. This assassination is all part of the plan of Nokov, who is attempting to gather power by killing other divine children and apparently Sigrud has to plan a significant plan in foiling his rise to power.
I really enjoyed City of Miracles, which rounded off the series very nicely, and I look forward to seeing more novel-length stuff from this author - I also plan to nominate the series for next year's Best Series Hugo.