The story of Lucas and Nathan's father, Dan Scott, is occasionally explored through flashbacks, which show his relationships with Karen Roe, Lucas's mother, and Deb Scott, Nathan's mother, and how he ended up with one woman rather than the other. He had a high school romance with Karen, resulting in Lucas's birth, but he refused to claim Lucas as his son. Leaving Karen, he married Deb, and the couple bore Nathan. Seventeen years later, Deb begins a strong friendship and partnership with Karen.