Because he planned to write Mirror Mirror but noticed there should be a book in between where Harry deals with his trauma.
All the other books have been planned or rather outlined before Storm Front was published. Twelve Months is a necessary addition.

This isnt the first time its deviated though from that outline, right? IIRC Changes was supposed to be 10, or was that some Mandela effect memory I am having?

This might be an unimportant detail but its stuck in my head.

How long has Rashid been the Gatekeeper and who did he replace?

Maybe it doesn't matter.

The last book before the BAT will be the time travel book, to "plug any continuity holes".

Is there a list of continuity errors posted anywhere?

In Peace Talks Lara’s second favor is to have Harry help him with getting Thomas out. But in essence doing so violates Winter Law by violating the accords. So does this mean the favor outweighs the law or does it mean that Harry can do it as long as he does it without being caught in violation??

I only ask this question because in Cold Days it’s established that even verbalizing that he is going to violate Winter Law damn near capacitates him (with Lakuna).

I feel like there is a bit of contradiction here. But maybe I am misunderstanding the difference between Winter Law and the Accords.

My current running theory is the despair Harry is feeling (noted during Instinct) is that this despair leads to events of Mirror Mirror (after resolving the marriage issue). The climax of Mirror then directly leads to the events of Murphy returns through some act of the White God for what I believe will be the final exclusively Denarian book.

Rereading it again it’s actually unclear but I took it that it was a wizard. Page 395, US Hardback.

Harry is talking to Ebenezer.

“Fuego!” Shouted someone from the walls - and for a second I was hit with a little sting of insult. Someone was shouting “fuego” and it wasn’t me.

It’s such a random statement in that chaos to be random, right?