Good question. Amazon received the books in time for the yesterday's official release of When the Sirens Were Silent but they are showing the book as "out of stock." What I don't know is whether they had more orders than the number of books ordered in their first shipment and it is indeed "out of stock" or whether the first order is hung up in their warehouse. I suspect the former.
We received another order for 41 copies from Amazon today, so it suggests the number of orders Amazon is receiving is healthy.
As the author, I apologize for any inconvenience this may be causing. You are welcome to order directly from Mike Smith Enterprises, LLC, 4031 N. Tara Circle, Wichita, KS 67226. The cost is $15 for first class mailing. We generally put books in the mail the day after we receive your check.