INTRODUCTION
At first this was a novelette called “A Twelvemonth and a Day.” I revised and expanded it for book publication, whereupon the then editor stuck it with the ridiculous title Let the Spacemen Beware! My thanks to Jim Baen, now in charge, for recognizing that readers have more intelligence than they were once given credit for having. In return, I admit that he’s probably right in considering the original name too cumbersome; hence the new one.
Otherwise the tale is unchanged. It can stand alone without reference to anything else. However, you may be interested to know that it does fit into the same “future history” as the Polesotechnic League and the Terran Empire. Nicholas van Rijn, David Falkayn, Christopher Holm, Dominic Flandry, and quite a few more characters lived in its past. Now the Empire has fallen, the Long Night descended upon that tiny fraction of the galaxy which man once explored and colonized. Like Romano-Britons after the last legion had withdrawn, people out in the former marches of civilization do not even know what is happening at its former heart. They have the physical capability of going there and finding out, but are too busy surviving. They are also, all unawares, generating whole new societies of their own.
I do not, myself, believe that history will necessarily repeat itself to this extent. Nor do I deny that it might. Nobody knows. Equally uncertain, at the present state of our knowledge, is the validity of some assumptions about human genetics and psychobiology which I made for narrative purposes. Here is just a story which I hope you will enjoy.
—Poul Anderson, 1978