Roger Waite found his dream woman while attending college at Washington State University. After a whirlwind romance he and Mary Johnson wed and begin life together, only to have her emotional sanity unravel because of a history of abuse and attempted suicide. When children are born and pressures assail her, she descends into a manic depressive anxiety-riddled existence confounding Roger's plans for the ideal family he seeks. Realizing Mary's sister, Victoria, has been a stabilizing influence for her as they grew up in Seattle, he enlists the young teenager's assistance to keep his wife from attempting suicide again. As the adolescent develops into a virtual twin of her older sister, which reminds Roger of the woman he met in college, forbidden feelings emerge. Victoria harbors desires to meet a person like her brother-in-law who can instill in her the changes she observed in her sister after meeting Roger. She cultivates an emotional attraction to him which she contrives to consummate as her first physical experience with a man. Can Roger and Mary save their romance or will he succumb to the allure of a young resolute teenage twin?