What is the main conflict in A Sport and a Pastime by James Salter?

The story's narrator—who remains anonymous throughout the novel—moves to a small French town named Autun where he is unexpectedly joined by the brilliant though unconventional Philip Dean. The narrator quickly comes to admire him. When Dean becomes involved with a young French girl named Anne-Marie he starts to obsessively piece together—from facts and his own feverish imagination—their time together. Dean ultimately leaves everything in France behind for America but dies in a car accident not long after his return.