The plot centers on Nina Leeds, the daughter of an Ivy League professor, who is devastated when her adored fiancé is killed in World War I, before they have a chance to consummate their passion. Ignoring the unconditional love of the novelist Charles Marsden, Nina embarks on a series of sordid affairs before determining to marry an amiable fool, Sam Evans. While Nina is pregnant with Sam's child, she learns a horrifying secret known only to Sam's mother: insanity runs in the Evans family and could be inherited by any child of Sam's. Realizing that a child is essential to her own and to Sam's happiness, Nina decides on a "scientific" solution. She will abort Sam's child and conceive a child with the physician Ned Darrell, letting Sam believe that it is his. The plan backfires when Nina and Ned's intimacy leads to their falling passionately in love. Twenty years later, Sam's "son" Gordon Evans is approaching manhood, with only Nina and Ned aware of the boy's true parentage. The meaning of the title is suggested by the aging Nina in a speech near the end of the play: "Our lives are strange dark interludes in the electrical display of God the Father!" --Wikipedia.com.