With the permission of the heads of the Security Administration, I became familiar with the cases designated by the codes: “Crystal Mirror” and “Danube”, after which this story appeared, which, I hope, will interest readers. The characters in the story are not made up, I just changed their names. Some pages of the book are original documents and reports taken from my cases. I did not touch upon only those events that might seem too implausible to readers. The circumstances of the capture of the gang leaders in 1946-1947 were in fact much more sensational than those that I described in the story. I have limited myself here to talking about only one event...