S2·E10 A Gentle Rain

A resident of 'The World Below' named Kanin—about to celebrate his first wedding anniversary below—is recognized by a woman in 'The World Above' as the driver who killed her small son in an accident sixteen years ago, the real reason Kanin retreated to the tunnels. Catherine inadvertently discovers his warrant and doesn't want to force Kanin to leave his family, but Vincent convinces him to face his responsibility and give closure to the grieving woman.