A terrorist holds Ducky, Gerald and Kate hostage while the rest of the NCIS team tries to figure out how the terrorist got inside and how to get their people out safely.
Harry Kim arises one morning to find he is back in San Francisco on Earth with his girlfriend Libby. He learns that in this reality, he never served aboard Voyager, but instead works in Starship Design at Starfleet Headquarters. Desperate to set things straight, the only person who can help him is lowlife Tom Paris, who has no idea who Harry is.
A kiss between Doogie and Janine becomes problematic. Raymond's estranged father shows up in the ER.
Jesse's grandparents, Gina and Iorgos Katsopolis, visit from Greece.