That was when I realized that silly Gary has never written it down, so here for the record is the book sequence:
The Pericles Commission
The Ionia Sanction
The next book in line has working title The Marathon Conspiracy. Working titles don't always stick, so stay tuned on that.
Each book is written to stand on its own, so technically it doesn't really matter in what order you pick them up. I know for sure some readers have come to the series starting with book 2 or 3, and then gone to Pericles Commission.
Of course if a character appears in a later book, then you know they survived any earlier books! Beyond that unavoidable information, I'm careful to omit spoilers on who did it from earlier adventures.