Plot

Capt. Janeway begins the episode with a holodeck program set in ancient England – 1700s to 1800s – acting out a story. In the middle of her program, Ensign Kim alerts her to an accident with Commander Chakotay

Chakotay

Chakotay , played by Robert Beltran, is a character in Star Trek: Voyager. He is the First Officer of the USS Voyager.-Character biography:...

 and Chief of Security Tuvok

Tuvok

Tuvok is one of the main characters on the television series Star Trek: Voyager. Tuvok is a Vulcan who serves as the ship's chief of security and its chief tactical officer. Tim Russ portrayed Tuvok throughout the show's run, from 1995 to 2001....

 who are found unconscious on a shuttle returning to Voyager

USS Voyager (Star Trek)

The fictional Intrepid-class starship USS Voyager is the primary setting of the science fiction television series Star Trek: Voyager. It is commanded by Captain Kathryn Janeway....

, and are transported directly to Sickbay, where Chakotay is pronounced brain dead. Captain Janeway

Kathryn Janeway

Kathryn Janeway, played by Kate Mulgrew, is a fictional character in the Star Trek franchise. As the captain of the Starfleet starship USS Voyager, she was the lead character on the television series Star Trek: Voyager, and later, a Starfleet admiral, as seen in the 2002 feature film Star Trek...

 decides to investigate the site, a dark matter

Dark matter

In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

 nebula, for the alien ship which the shuttle's logs record as attacking the shuttle with an energy weapon and to learn why someone would steal Chakotay's neural energy. But the ship changes course en-route, and although the command was given from the helm, Lieutenant Paris

Tom Paris

Thomas Eugene "Tom" Paris, played by Robert Duncan McNeill, is a character in the television series Star Trek: Voyager. Paris serves as the chief helmsman and an auxiliary medic aboard the USS Voyager...

 denies making any change. Helm control is transferred to another station while the course change is investigated. Torres, in sick bay, uses a Healing Wheel (a spiritual talisman used by Chakotay's people) to help Chakotay recover. It is used in Vision quests when the soul walks along the wheel, but when the person is in a coma or nearing death, is made in to a sign post to lead the person back. The Doctor points out a flaw in Torres' use, and that it may not be enough. In her quarters, Kes senses a presence – to which the viewers see through the eyes of the entity – and tells Neelix of the phenomenon.

Another course change is made and Paris is again identified as the culprit, this time with incontrovertible evidence from Torres' statement and Paris' DNA. Paris is confined to Sickbay for examination to see if he is being controlled. Tuvok finds the trail used by the engines of the ones the Voyager is after, and see its flight pattern is indicative of avoiding obstacles in the nebula, so Janeway orders to follow the exact same flight path. Soon, the warp core is shut down and the main computer crashes. Chief Engineer Torres

B'Elanna Torres

B'Elanna Torres is a main character in Star Trek: Voyager played by Roxann Dawson. She is portrayed as a half-human half-Klingon born in 2349 on the Federation colony Kessik IV. Torres joined the Maquis in 2370 and was serving on the Val Jean when brought to the Delta Quadrant...

 apparently made the order but has no recollection of doing so. Torres is also sent to Sickbay for examination, and the Doctor discovers a unique memory pattern occurring once in Torres' mind and twice in Paris', appearing at precisely the moments where they made actions of which they have no recollection. It becomes apparent that an entity is aboard the ship, controlling the minds of crew-members. This is reinforced by Kes

Kes (Star Trek)

Kes is a character in the television series Star Trek: Voyager, played by Jennifer Lien.She was a regular for the first three seasons, leaving the show in the season four episode "The Gift". She made one guest appearance two seasons later....

, whose undeveloped psychic powers detect a presence. Tuvok offers to do a mind meld to help her gain better control, but before he can, the two are knocked unconscious while on the Turbolift with Kes into a coma.

To prevent the alien from taking control of herself and ordering something disastrous, Janeway decides to transfer all of the ship's command codes to the holographic Doctor, who cannot be mind-controlled. The Doctor discovers wounds on Kes not consistent with an energy attack, but a physical assault and Tuvok reports this to Janeway, who speculates that he might have been controlled in the turbolift. Before they can ask the Doctor, the alien entity has taken the E.M.H. offline and the command codes have been reverted back to Janeway. Janeway decides to share the codes with Tuvok, so that commands must be confirmed by both of them to take effect. Torres presents evidence to Janeway that there was no ship in the Nebula, and that Tuvok was under the alien's control when he returned. As soon as a course is plotted, Paris arrives to tell the Captain that Kes was taken down by a Vulcan Nerve Pinch, as detailed in the Doctor's notes prior to shutdown.

After seeing that the trail of the "ship" does not leave a distorted spacial residue, Janeway orders the Voyager not to head into the nebula . However, before this can happen, Tuvok takes control of the ship, under the influence of the alien, holding all bridge crew hostage with his phaser. He orders Voyager into the nebula, and through Tuvok, the alien explains that he belongs to a group of noncorporeal entities called the Komar, and require neural energy - from the minds of the crew - to sustain them. But before Voyager can fully enter the nebula, the warp core is dumped by Torres, though she has no recollection of doing so after becoming possessed. It becomes apparent that there are two entities on board, battling with each other for control of the ship. Janeway reveals from what has happened that the entity which made Torres dump the warp core is Chakotay, as evidenced by the fact that his authorization was given for the command, to keep the crew from going into the nebula. The crew manage to overpower the possessed Tuvok while he attempts to navigate Voyager into the nebula, and the alien entity leaves the ship when a prepared magneton scan is activated rendering Tuvok unconscious.

Janeway orders the ship out of the nebula, with Chakotay possessing Neelix for a moment to tell the Captain a clue as to escape. The Healing Wheel stones are moved into new positions, and after putting a star map of the nebula of it, they find three stones overlap planetoids in the system. The crew follow the map and make it out of the nebula. After reacquiring the warp core, The Doctor helps Chakotay's consciousness return to his physical form.

External links

• Definition of the word Cathexis at die.net