Star Trek: Voyager Season 4 Episode 21

Stardate: 51781.2. Voyager is forced out of warp by the detection of a dangerous and powerful particle called ‘Omega’ which only Janeway and Seven of Nine know about on board the ship. Due to the nature of the particle, only Starfleet Captains are informed and are ordered to destroy it at all costs, as it has the power to destroy subspace. Janeway must enlist the help of the senior crew on a need-to-know basis in order to destroy it safely.