Warren has bolted from the mansion yet again. Tired of having to keep tabs on Warren with Cerebro, Xavier planted a mobile device with GPS to track him each time he took off.
Jean has tracked Warren’s whereabouts to Brazil. She suspects that Warren’s parents’ visit had to do with Warren taking off without notice.
The day before, Warren’s parents made an unexpected visit to the mansion. After briefly introducing his classmates (and friends) to his parents, Warren is pulled aside by his parents with private yet urgent news. His favourite aunt, Mimi, had gone missing in Brazil while photographing the Iguacu Falls.
Back in Brazil, Warren has started to take to the skies when Jean finally manages to squeeze the secret out of Warren. She is slightly miffed that Warren did not think to ask his friends for help.
Reception starts to get lousy as Warren approaches the waterfall. While Warren converses with Jean about his aunt, the traveller, Bobby loudly announces the mail delivery, including a postcard from Warren’t aunt. It details her intentions to investigate “The Devil’s Throat”, “the place that several falls merge”.
Warren spots a rope hanging down from a rock outcrop. He dives into the waterfalls to search for his aunt. Jean, realising that Warren has taken the plunge into uncertain danger, frantically urges Warren not to stop, to no avail.
Flying through the waterfall, Warren finds himself in a hidden city, “The Land of Mists”. The inhabitants are not at all alarmed by the presence of a winged man. They point to the tower when Warren inquires about his aunt.
His aunt shows him around the land full of strange creatures. The people who live here were descendants of natives and “peaceful Portuguese colonists” who sought refuge when the conquistadors invaded. Light comes in the form of “bioluminescent algae” on the walls. She introduces Warren to Bera, a local girl she had befriended and spoke highly of Warren. Bera appears to be smitten by Warren from Aunt Mimi’s stories alone, and kisses Warren as her way of greeting. Warren is received at a huge banquet thrown by the locals.
The next day, the X-Men come searching for Warren. They find him alive and well, and are awed by this strange and amazing place. They are however, unable to convince Warren to return home with them to New York.
Back at the mansion, the X-Men relate their story regarding Warren’s absence to Xavier. Warren had chosen not to return because he felt accepted there by the entire society for who he truly is. The X-Men are reacting emotionally to the loss of their team mate and friend. But Xavier reminds them that he wishes for nothing more than happiness and peace for his students, and urges them to “let go” if they must, for Warren’s sake.