In this third and final instalment of Leo's travelling adventures, Leo has been travelling for four months, but an amorous snub received while she is in Paris makes her want to call it a day and go straight home without completing the planned six months of her trip. Her aunt's insistence and a surprise visit help Leo reconsider her hasty decision and, just as she was expecting to return to Santiago de Compostela in Galicia, where she is from, she finds herself on a transatlantic flight to Buenos Aires. When she was planning this trip with her friends, who ended up pulling out, she had never envisaged travelling to South America, but now she will be swallowed up by the infinite grid of Argentina's capital city, she will be pursued by the shadow of Argentina's first serial killer as far as the southernmost city in the world, Ushuaia, she will be entranced by the magical beauty of the famous Perito Moreno Glacier with all its shades of blue, she will finally fulfil her dream of visiting Machu Picchu in Peru, she will be unimpressed by the floating islands of Lake Titicaca, be doused in sugar in the white city of Arequipa and walk under the grey Lima sky. Back in Buenos Aires, at the end of six months, she will face a critical decision, which may lead her to the author of all those messages that have appeared in front of most of the monuments she has visited: 'I Love You Leo A.' Who has been painting these messages wherever she goes? And having once set out on her travels, will Leo ever manage to return back home?