Johnston (The Women, "3rd Rock from the Sun") will appear as Lily, the demanding leading actress, with Chlumsky ("My Girl," Fabulous Life of a Size Zero) as her ingénue understudy with aims to take her place. Additional casting will be announced shortly.

Martin Platt directs Maurine Dallas Watkins' backstage comedy that will officially open at the Lucile Lortel Theatre Dec. 7 and run through Dec. 20.

Johnston headlined a reading of So Help Me God! last summer at the Lortel. Watkins is the late playwright of Chicago (the basis for the Kander and Ebb musical), as well as the screenplays "Libeled Lady" and "Roxie Hart."

Chlumsky has appeared on screen in "Uncle Buck" and "My Girl," as well as in stage productions of Unconditional, Measure for Measure, Darwin in Malibu, Half Life and The Butcherhouse Chronicles.