Cipher book

A Peren book on writing letters that say one thing to anybody who reads them and another to anybody who has the book. The method it teaches runs on the moons: an ordinary phrase about the calendar carries a date nobody outside the correspondence would think to look for. By the end of the month is not the end of a month. It is the next new moon of Awalan.

Koa and Mikhail turned it up going through Alex Westwood’s study while Westwood was being walked out, along with more of the correspondence it was written to unlock. It was the book that gave them the real deadline for the shipment at Haudh-Gwenn: a week from the following day, which was just enough time to get downriver.

Whether the book went to the constable with the rest of the evidence or stayed in the party’s hands was never written down. Its trick outlived it either way: a week later at Haudh-Gwenn they were still keeping the slavers’ calendar by Awalan’s new moon.