In 1981, Karen Erickson (plaintiff) helped establish Trinity Theatre, Inc. (Trinity) (defendant) and maintained several positions there until 1991. During her time at Trinity, Erickson completed two plays, Prairie Voices and Much Ado About Shakespeare (Much Ado). Erickson completed a third play, Time Machine, a project Erickson produced independently of her positions with Trinity. While developing Prairie Voices and Much Ado, Erickson conducted improvisational idea sessions with Trinity’s actors. While suggestions by some of the actors were adopted into the completed scripts, Erickson retained final control over what material was chosen. For Time Machine, Erickson collaborated with Paddy Lynn, who was initially identified as co-author of the script and received royalties from performances. Erickson later denied that Lynn was ever intended to be a joint author of Time Machine. In 1988, Erickson and Trinity reached an agreement under which Trinity would pay royalties to Erickson for performances of the plays. Trinity stopped paying royalties to Erickson in 1990. After obtaining copyright registration for the three plays, Erickson asked Trinity to cease all performances, but Trinity refused. Erickson responded with a copyright-infringement suit, and the district court affirmed the decision of a magistrate judge to enjoin Trinity from performing Erickson’s plays. Trinity appealed.