Seven hears voices and begins walking round the the cargo bay. She arrives in the mess hall and begins to stuff her face with food, tearing at a piece of chicken. In the metal reflection a Klingon can be seen.
Naomi Wildman begins to follow Seven around. Seven finds her and asks her what she is doing. Naomi says she is trying to be perfect like Borg do. Suddenly Seven hears voices and her mind changes into a child's. She goes off to play with Naomi.
Seven gets a comm call from B'lanna. Seven returns to a normal and is unaware what has happened to her. She goes to help B'lanna and then attacks he. She then takes out two security officers and runs for it.
However she soon changes to a Klingon and goes for Tuvok who stuns her. She wakes up in sickbay still hearing the voices. The Doctor uses a neural inhibitor to make them go away.
The Doctor notices several new neutral patterns have surfaced in Seven's mind. Seven says it could be the interlink frequency of the Borg communicating with her from the debris field. Voyager sets a course towards it.
The Doctor checks Seven's regeneration cycle logs and found that it was interrupted - revealing the identify of the "midnight snacker." Seven seems agitated. Voyager arrives at the debris field and Seven identifies the source as a Borg Vinculum.
Janeway agrees to beam it aboard. It is beamed to engineering and Seven goes down to see it. The voices return but The Doctor adjusts her neural inhibitor levels. Seven begins working to disable it and finds a virus in the Vinculum. It appears to be attacked the Vinculum after the Borg assimilated a shuttle.
Seven and The Doctor tell Janeway that species 6339 caused the virus after nearly being wiped out by the Borg. However the inhibitor goes offline and Seven changes into a Ferengi who tries to buy the visual display in Astrometrics.
The Doctor and Janeway convince Seven to go to sickbay. She offers to sell them new medical equipment. The Doctor erects a force field around her. Seven begins to turn again and then goes back to normal. Janeway tries to reassure her but Seven is not so confident.
B'lanna begins to try and disable the Vinculum. Meanwhile The Doctor notices Seven's neural patterns is stabilising. However the Vinculum adapts and its power output increases. The Doctor tells Janeway her neural patterns have disapproved.
Voyager sets a course for species 6339. Tuvok says he will attempt a mind meld with Seven to bring her pattern to the surface. Janeway makes contact with species 6339 who tells her that the virus in the Vinculum was put their on purpose to destroy Borg ships.
Janeway asks them to help them treat Seven. The head alien tells them there is no way to treat Seven and that the Vinculum must be returned to the debris field so more Borg will be infected.
Seven comes round and finds herself restrained. The Doctor tells her about Tuvok's mind meld idea. She agrees before the other personalities take over.
Tuvok is meditating and then heads down to sickbay. Meanwhile the alien vessel perpares to take the Vinculum by force. The Doctor says to Tuvok "all these new personalities floating around, its a shame we can't find one for you."
Tuvok initiates the meld and finds himself in a warped cargo bay full of different aliens. He goes looking for Seven but is mobbed by the aliens. The alien vessel begins to attack Voyager.B'lanna says she can take the Vinculum offline in 60 seconds.
Power transfer systems are offline and The Doctor tries to shout at Tuvok to stop the meld but is unsuccessful. He continues to try and battle his way to Seven.
B'lanna begins to take the Vinculum offline but the field emitters go down. Janeway switches to backup power and B'lanna manages to de-activate the Vinculum. The other personalities disappear and Tuvok ends the meld.
Janeway gives the order to beam the Vinculum back into space and the aliens break off. Seven revcovers and goes to see Naomi. She gives her information to study and asks her to teach her how to play Caduscat - "I wish to participate in recreational activities."