Maxwell Smart must defeat the sinister Mr. Big, who is using a device called the Inthermo to threaten New York City. Michael Dunn, who would go on to star as The Wild Wild West's Dr. Miguelito Loveless, stars as KAOS's Mr. Big. This pilot episode introduced a running gag of a captured Maxwell Smart trying to bluff his way out by claiming that an overwhelming force is going to rescue him starting with "Would you believe..." and those who capture him saying either "I find that hard to believe " or "I don't think so...".
