"Good Shepherd" is the 140th episode of the science fiction television series Star Trek: Voyager. It is the 20th episode of the show’s sixth season.

After a routine shipwide efficiency analysis, Seven of Nine determines that three of Voyager's crewmen are not performing at acceptable levels. Whereas such a problem on a starship would normally be remedied by a transfer to less challenging assignments, this option is not available to the crew of the Voyager, which is stranded tens of thousands of light years from Earth.

Captain Janeway decides to take the three crewmen under her wing, and against the advice of Seven of Nine, brings them along on an astronomical study in the Delta Flyer in order to form a rapport with them. The three crewmen are science officer William Telfer, a hypochondriac; Tal Celes, a Bajoran whose substandard work requires constant double-checking by others; and the asocial Mortimer Harren, who is interested only in cosmological theories and has found an assignment where he can sequester himself on Deck 15 and pursue this subject between occasional duties.

During the mission, an unknown, invisible force strikes the Delta Flyer, knocking its propulsion offline and neutralizing 90% of its antimatter fuel. Janeway transmits a distress call to Voyager. Harren suggests that a comet-like assemblage of dark matter is responsible, and proposes ejecting the remaining antimatter, which will attract another impact; but Janeway declines, arguing that more evidence is needed for Harren’s theory before she will act on it. She decides to fire a photon torpedo at the force.

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