Conspiracy (Star Trek: The Next Generation) - Plot

Plot

While the Enterprise is en route to Pacifica, Captain Walker Keel (Jonathan Farwell) of the USS Horatio contacts Captain Picard over a secure channel, and requests a face-to-face meeting. Once they arrive at Dytallix B, the crew discover the Horatio and two other Federation ships, but they are unresponsive to the Enterprise's communications. Picard beams to the surface and is met by Keel and the other captains. Keel reports strange orders and events from Starfleet Headquarters, and expresses concern of a conspiracy. Picard refuses to accept this without proof, but Keel warns him to remain cautious. The ships depart the planet and resume their original orders. Picard has Data (Brent Spiner) review Starfleet's recent records for any anomalies. As they near their destination, the crew discovers the destroyed remains of the Horatio. Data completes his study and finds several strange orders from the senior levels of Starfleet. Picard informs his senior staff of the conspiracy theory, and orders the Enterprise to Earth.

On arrival, Picard and Commander Riker (Jonathan Frakes) are greeted by three Admirals, Savar (Henry Darrow), Arron (Ray Reinhardt), and Quinn (Ward Costello), along with Quinn's assistant Lt. Commander Remmick (Robert Schenkkan). They are surprised by the Enterprise's presence, but invite Picard and Riker to dinner. Quinn requests to beam aboard the Enterprise for a tour, upon his arrival Picard discusses matters with him and comes to believe that he is an impostor and warns Riker of his concerns. Picard leaves to beam down to earth to attend the dinner. Meanwhile, Riker visits Quinn's quarters on the Enterprise and questions him about what he has in the small box he brought with him. Quinn tells Riker of a parasitic creature within the box. Riker attempts to leave but Quinn throws Riker across the room. A security team arrives to subdue Quinn, who is able to withstand an great amount of phaser-fire before he collapses. Dr. Crusher (Gates McFadden) finds a small protrusion on the back of his neck, and she discovers that a bug-like parasite has latched itself onto Quinn's brain and is controlling him. Dr. Crusher warns Picard of this incident, who reveals that he travelled unarmed to the surface.

A bowl of living larvae is served at the meal, and Picard attempts to escape, only to find Riker blocking his way. The Admirals see a prosthetic protrusion on the back of Riker's neck and allow him to dine, believing him to have a parasite as well. They reveal that the parasites are seeking to take over Starfleet, using humanoids as hosts. Riker attacks the Admirals, using a phaser set on full power to kill the infected officers. One by one, Picard and Riker kill the infected, causing parasites to leave the dead hosts and flee. One of the parasites scurries under a closed door and Picard and Riker follow it. They find Remmick ingesting the parasite to join several others inside him. Picard and Riker fire upon Remmick, destroying his body but freeing a giant parasite; the two continue to fire until it is destroyed. Dr. Crusher reports that the other parasites, including the one in Quinn, have shriveled up as they are unable to survive without the creature that was inside Remmick. As they help to settle matters with Starfleet headquarters, they find that before Remmick was killed, he had sent a signal to a distant quadrant of the galaxy, possibly as a homing beacon to guide an unknown entity to Earth.