Irreplaceable follows host Tim Sisarich (former Executive Director of Focus on the Family New Zealand) as he consults with experts around the globe to determine whether the concept of the traditional family is still meaningful today. The film explores questions such as "What is family?", "What is marriage?" and "What is the significance of fatherhood and motherhood?" Among the many experts interviewed in the film are: Michael Medved (radio host, commentator, author), Eric Metaxas (co-host of Breakpoint), Dr. Roger Scruton (British philosopher), Dr. Anne Moir (acclaimed neuropsychologist, founder of Brainsex Matters), Helen Alvare (professor of Family Law at George Mason University), Jonathan Last (senior writer at The Weekly Standard), and Carey Casey (CEO of National Center for Fathering).