Season 3 of “Star Trek: Picard” reunites seven cast members from “Star Trek: The Next Generation,” teasing fans with the possibility of other cameos. In Episode 7, titled “Dominion,” Seven of Nine (Jeri Ryan) reaches out to an old Voyager crewmate, Tuvok (Tim Russ), for help with a kidnapping, offering a brief reunion for “Voyager” fans.