Under her masculine nom de plume, Germain shared her work on Fermat’s Last Theorem in a letter to University of Göttingen professor Carl Gauss, one of the most famous mathematicians and astronomers of the day. The letter began with an apology: “Unfortunately, the depth of my intellect does not equal the voracity of my appetite, and I feel a kind of temerity in troubling a man of genius.” Gauss wrote back with words of encouragement: “I am delighted that arithmetic has found in you so able a friend.” Gauss did not learn of her true identity until 1807. When Napoleon’s forces moved into Prussia, Germain feared that Gauss might come to the same end as Archimedes, so she asked a commander she knew in the French Army to ensure his safety. He sought out Gauss and told him that his life was safe on account of the intercession of one Sophie Germain. Gauss had no idea who his mysterious benefactor was until Germain admitted her deception in a subsequent letter. Gauss was delighted by the turn of events: “A taste for the abstract sciences in general and above all the mysteries of numbers is excessively rare…. But when a person of the sex which, according to our customs and prejudices, must encounter infinitely more difficulties than men to familiarize herself with these thorny researches, succeeds nevertheless in surmounting these obstacles and penetrating the most obscure parts of them, then without doubt she must have the noblest courage, quite extraordinary talents and superior genius.” For all their corresponding and mutual admiration, Gauss and Germain never met. He persuaded the University of Göttingen to grant her an honorary degree, but before she could make the trip from France, she died at the age of fifty-five after a two-year battle with breast cancer.