The role of Sheila Shea was originally written for 'Sandy Dennis'. Paul Dooley was seriously allergic to cats though, and when cat-lover Dennis would come to the script readings with up to five cats at a time, he was briefly hospitalized. As a result, 'Allan Nichols' re-wrote the role of Sheila Shea from an Earth Mother type to the young singer/groupie played by Marta Heflin.