

Leaky attempts to take a facemask, but cannot master it, so a message from future Umbo warns them not to try it. Umbo escorts Loaf back to Leaky, hoping she will accept him with his facemask. Rigg eventually decides to do the latter. Rigg explores every wallfold on Garden with Ram, in order to decide whether the walls should come down or each should be preserved without the influence of the others. They decide to send Noxon to Earth to attempt to prevent the destroyers from coming to Garden, while Rigg will stay on Garden to assess the wallfolds and help with the war in Ramfold.

The novel picks up where the events of Ruins left off: Ram, Rigg, Noxon (Rigg's duplicate from the future who has come back to prevent him from killing Ram Odin), and Vadeshex are in the control room discussing what to do about the seemingly inevitable arrival of the visitors from Earth, followed by the destroyers. Their skills and abilities are put to the ultimate test as they try to end the war between worlds before it can begin in this epic and explosive conclusion. They travel through the history of Garden and each Wallfold, hoping to uncover the reason that the visitors from Earth will send the destroyers and attempting to prevent this outcome without having to destroy Earth preemptively. As they struggle to determine how to prevent the planet's impending doom, they are forced into an impossible moral dilemma: whether it is justified to sacrifice one world for another, especially when one of those worlds is Earth, the Cradle of Humanity. In Visitors, Rigg, Umbo, and Param have determined that humans are the destroyers that bring about the end of their world.
