Nikki Leigh

After Ducky is attacked by a man claiming to have information about his half-brother who died decades ago, the NCIS team searches for the perpetrator, as Ducky recalls the final emotional days he had with his sibling. Also, with the holidays approaching, Bishop and Jake (Jamie Bamber) discuss the future of their relationship. Adam Campbell returns as "Young Ducky."

Walden joins a group for adoptive fathers, and finds it to be a nice escape from Alan.

Thomas confronts Ridge about the real reason he was sent away to Paris.