Tlooth by Harry Mathews
This novel begins in a Russian prison camp at a baseball game featuring the defective Baptists versus the Fideists. There is a plot (of sorts), one of revenge surrounding a doctor who, in removing a bone spur from our narrator, manages to amputate a ring and index finger, a significant surgical error considering that the narrator is, or was, a violinist. When Dr. Roak is released from prison, our narrator escapes in order to begin the pursuit, and thus begins a digressive journey from Afghanistan to Venice, then on to India and Morocco and France. All of this takes place amid Mathews's fictional concern and play with games, puzzles, arcana, and stories within stories.