Christina Applegate

Christina Applegate is discovering a side of her family she knows nothing about on TLC's Who Do You Think You Are?

On Tuesday's episode, Applegate wants to learn about her paternal grandmother, a family member whom neither she nor her father ever really knew. From wedding announcements to society notices, Applegate is pretty surprised when she digs deep into her past.

Exclusive First Look: TLC gives Who Do You Think You Are? new life

Watch our exclusive clip from the episode, which airs on Tuesday at 9/8c on TLC.