Behind the towering walls of the Vatican, a private battle unfolded in February when Pope Francis was rushed to Gemelli Hospital with life-threatening double pneumonia. For most people, pneumonia can be a recoverable illness, but for the 88-year-old pontiff, the risks were far greater. Having lost part of a lung to pleurisy at the age of 21, his compromised respiratory system left him particularly vulnerable to severe complications. This latest infection would leave a deeper scar than before, one his body would not recover from.