Timeshapers Rigg, Umbo, and Param must stop the Visitors from ordering the destruction of the planet Garden. Can they find a way to save their home world -- without destroying all human life on Earth? Everything they've tried so far has failed -- they can't even figure out why the humans from Earth would want to wipe out this eleven-thousand-year-old colony world. So to find the answer, Rigg must visit every wallfold on Garden to discover what the Visitors fear so much, while his duplicate, Noxon, takes a time-twisting route back to Earth in hopes of changing the future from the enemy's side. Neither mission can succeed without the help of allies who have proven themselves to be untrustworthy again and again. Meanwhile, Umbo struggles to save the lives of the people he loves without upsetting the whole course of history, while Param and her counselors try to save their homeland from the cruelest of tyrants -- Param's mother. Yet looming over their actions is this question: Will all of their efforts come down to a choice between human life on Earth or human life on Garden? - Jacket flap.