Piper Through time and space

Ten years after the adventures of "The Rip in Space," the Murrays reunite for Thanksgiving. Meg and Calvin have married in the meantime, the twins are studying and Charles Wallace continues to research tesserung with his father. But the family idyll is marred when Meg's father receives a call from the president: A political situation appears to be on the verge of escalation and nuclear war threatens the Earth. Charles Wallace meets the winged unicorn Gaudior in his family's garden, with whom he undertakes a journey through time to save the earth. But the sinister Echtroi have not given up yet and try one more time to stop Charles Wallace.