The pen pal, the study buddy, the "best" friend - there are many forms of male friendship. The Berlin cultural scientist Andreas Krass examines them all in his new book, from antiquity to the present. Twenty stories of male friendship, from Homer to Wolfgang Herrndorf, are analyzed and related to a corresponding epochal philosophical text. The focus is on non-homosexual friendships and their stories of passion, which follow a pattern: Why must one friend die before the other can speak passionately about their friendship? And how does this change over the course of history? A literary and cultural historical investigation full of new and surprising insights.