"The Best of Both Worlds" is the 26th episode of the third season and the first episode of the fourth season of the American science fiction television series Star Trek: The Next Generation. It comprises the 74th and 75th episodes of the series overall. The first part was originally aired on June 18, 1990, and the second on September 24, 1990 in broadcast syndication. The story occurs across stardates 43989.1 – 44002.3 (December 2366/January 2367 by the Okuda timeline).

Set in the 24th century, the series follows the adventures of the crew of the Federation starship Enterprise. In this episode, the Enterprise must battle the Borg who are intent on conquering Earth, with a captured and assimilated Captain Picard as their emissary. Part 1 was the finale to season three, while Part 2 was the premiere of season four. It is considered one of the most popular TNG episodes.

The Starship Enterprise responds to a distress call from a Federation colony and arrives to discover the colony gone. The Federation suspect the Borg—cybernetic humanoids that assimilate individuals into their hive mind.

Starfleet Admiral Hanson arrives on Enterprise with Lt. Commander Shelby, an expert on the Borg, who assists the crew in determining the cause of the colony's disappearance. Hanson informs Captain Picard that Commander Riker has been offered the command of a starship and suggests that Riker take the position. Although there is tension between Riker and Shelby—who intends to take over his position of first officer—they confirm that the colony was assimilated by the Borg. Hanson advises Picard that another Federation vessel encountered a strange "cube-like" vessel before sending a distress call that ended abruptly. Enterprise moves to intercept and confronts a Borg cube.

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