Star Trek: Enterprise (2001)

Season 1: Episode 11

When the Enterprise comes in contact with an alien vessel transporting stargazers to observe a spectacular stellar event, Archer invites them aboard the ship not realizing that Silik, a Suliban enemy, is among them. Archer quickly realizes that Silik is engaged in a nefarious time-travelling mission and must stop him before he can tamper with the course of history.