Voyager is confronted by the Hirogen after usings their ancient network of relay stations to retrieve letters from home.
4-25: Hope and Fear
Hope turns to fear when a decrypted Starfleet message communicating a way home proves false, forcing Janeway to face the consequences of a past decision.
4-18: The Killing Game, Part I
Their memories erased, Voyager’s crew are placed into a World War II holoprogram to be studied and hunted by the Hirogen.