There are 21 ways to ruin a marriage and that's enough to convince Sanna that falling in love is folly. As her extensive studies show ‘Divorce is a natural and probable consequence of falling in love.’ Love and sex are two different things, and she prefers the latter, in an intoxicated state if possible. Marriage is a business agreement. And to prove her point she is conducting an extensive study interviewing couples from their marriage to their inevitable divorce. When Aleksi comes into her life, she finds herself smitten and her world is about to be turned upside down. If there are 21 ways to ruin a marriage, there must be 21 ways to fall in love.