It may be thought by some that in the pages which follow I have painted in too lurid colours the horrors of a foreign invasion of England. Realism in art, it may be argued, can be carried too far. I prefer to think that the majority of my readers will acquit me of a desire to be unduly sensational. It is necessary that England should be roused to a sense of her peril, and only by setting down without flinching the probable results of an invasion can this be done.