What is the main conflict in Pnin by Vladimir Nabokov?

Timofey Pnin is a Russian immigrant teaching Russian at a Waindell, a small college in the northeastern United States. Despite his inoffensive and quiet existence, he is regularly victimized by the thoughtlessness and even hatred of others towards him, most of all his manipulative ex-wife, Liza. He winds up losing his job at Waindell and is forced to leave the one place he was ever comfortable living.