Sumner comes back to Cheers, ostensibly to make amends with Diane, but with a deeper hidden purpose. His presence causes Diane to be embarrassed to be dating Sam, and also Sam to question his own ability to keep up with Diane's intellect.
- Shelley Long as Diane Chambers
- Ted Danson as Sam Malone
- Nicholas Colasanto as "Coach" Ernie Pantusso
- Rhea Perlman as Carla Tortelli
- John Ratzenberger as Cliff Clavin
- George Wendt as Norm Peterson
Recurring / Guest stars: