In the National Army Museum in London, U.K., a special exhibit features a curious box. The walls on the inside of the box are mirrors, each one reflecting another. Placed inside the box are dozens of cut-out horses. They are all white, unnamed, undefined. But as they reflect back and forth on the mirrors, the little cut-out horses are multiplied into infinity. The image, so simple, is a profound reminder that over eight million horses on all enemy sides died in the horrors of the First World War.