Jody and Carl, the only characters in Lonely Planet, are habitués of a sleepy little shop called Jody’s Maps in an unnamed American city. These middle-aged men, intricately rendered in Steven Dietz’s subtle, elegiac script, are being realized vividly by New York stage veterans Arnie Burton and Matt McGrath in a Keen Company production celebrating the 25th anniversary of the play’s premiere at Northlight Theatre in Evanston, Ill. Lonely Planet, winner of the PEN Center USA Award for Drama, was written when the arts were being defoliated by an epidemic beyond the American medical community’s control. AIDS is the background of the play, but not its subject.