"The Understudy," written by Ben Joelson and Art Baer, is all about Connie Evans (Jo Anne Harris), a seemingly forthright young lady who has signed on as a cruise director trainee, assisting Julie McCoy. Winning the favor of Capt. Stubing, Connie undermines Julie and nearly gets her job. In "Married Singles," Steve Allen and Polly Bergen are Durwood and Maisie, a married couple trying to have fun pretending they don't know each other. Ray Jessel wrote the script. In "Lost and Found, " Sandy Duncan and Jim Stafford play Sharon and Richard Baker, a young couple whose only child has died. During their voyage, they find new happiness through a runaway child, played by James Bond III.