War is waged by men; not by beasts, or by gods. It is a peculiarly human activity. To call it a crime against mankind is to miss at least half its significance; it is also the punishment of a crime. That raises a moral question, the kind of problem with which the present age is disinclined to deal. Perhaps some future attempt to provide a solution for it may prove to be even more astonishing than the last. While this book is a record of experience on the Somme and Ancre fronts, with an interval behind the lines, during the latter half of the year 1916; and the events described in it actually happened; the characters are fictitious. It is true that in recording the conversations, the men seemed at times to hear the voices of ghosts. Their judgments were necessarily partial and prejudiced; but prejudices and partialities provide most of the driving power of life.