Serge has been diagnosed with a variety of mental illnesses, and has been prescribed a "cocktail" of drugs to keep him stable. These are effective, but he often refuses to take them, since he dislikes their effects. Free from the drugs' influence, he quickly becomes manic and obsessive about trivial things; he frequently acts as an extremely eccentric tour guide for whoever happens to be handy. Despite his psychological disorders, Serge is for the most part a charismatic, likeable person (he can be viewed as a somewhat more liberal version of Joseph Heller's Yossarian).