Companion to the Newbery Award winner "A wrinkle in time" and "A wind in the door."

In this fateful hour -- All Heaven with its power -- The sun with its brightness -- The snow with its whiteness -- The fire with all the strength it hath -- The lightning with its rapid wrath -- The winds with their swiftness -- The sea with its deepness -- The rocks with their steepness -- The earth with its starkness -- All these I place -- Between myself and the powers of darkness.

In this companion to the Newbery Award winner A Wrinkle in Time and A Wind in the Door, fifteen-year-old Charles Wallace and the unicorn Gaudior undertake a perilous journey through time in a desperate attempt to stop the destruction of the world by the mad dictator Madog Branzillo. They are not alone in their quest. Charles Wallace's sister, Meg--grown and expecting her first child, but still able to enter her brother's thoughts and emotions by "kything"--goes with him in spirit. Charles Wallace must face the ultimate test of his faith and his will as he is sent within four people from another time, there to search for a way to avert the tragedy threatening them all.