The former "Seinfeld" co-stars will reunite in an episode of Louis-Dreyfus' comedy, "The New Adventures of Old Christine," CBS said Wednesday.
Alexander's character -- a lizard handler for children's birthday parties -- will go on a date with Christine, a divorced working mom.
"Old Christine" will return this winter. No date for the third-season premiere has been announced by the network.
Louis-Dreyfus, 46, won an Emmy for "Old Christine" last year, and is nominated this year. She also won an Emmy for "Seinfeld."
Alexander, 47, received seven Emmy nominations for "Seinfeld," which aired from 1990 to 1998.