Morphine

"Young Dr. Bromgard has come to a small country town to assume a new practice. No sooner has he arrived than he receives word that a colleague, Dr. Polyakov, has fallen gravely ill. Before Bromgard can go to his friend's aid, Polyakov is brought to his practice in the middle of the night with a self-inflicted gunshot wound, and, barely conscious, gives Bromgard his journal before dying"--Amazon.com.