Pope Leo XIV is embarking on the longest and farthest trip of his pontificate three weeks after lung cancer surgery. The U.S.-born Leo is returning home to Peru, where the former Robert Prevost lived for two decades as a missionary priest and learned to be the pastor he is today. Leo is also going to Argentina, the home of his predecessor, Pope Francis. It will be a homecoming of sorts there, too, since Francis never returned to Argentina after his 2013 election, leaving a complicated legacy that Leo will now have to navigate. Leo starts his journey Friday in Uruguay, the least Catholic, most secular country in all of Latin America.