"The Swarm" is the 46th episode of Star Trek: Voyager, the fourth episode of the third season. The episode follows two separate storylines. In the first one, Voyager must navigate through a region of space inhabited by a highly xenophobic alien race known only as "the Swarm." Any ship that enters space inhabited by these people is never heard of again. In the second, the Doctor begins suffering from memory lapses which leads to the possibility of his entire program breaking down.