Entity (episode)

"Entity" is the twentieth episode of the fourth season of Stargate SG-1.

Plot
When the SGC dial an unknown planet and send a MALP, they discover highly advanced life. Suddenly the MALP seems to start flying, and before the connection is lost, the computers overload. O'Neill cuts power to the gate manually, but computers are behaving as if controlled by an intelligence. Soon SG-1 realizes an alien life force has taken over the base's computer system. It uses cameras to follow their actions and shuts down the computers if necessary. When Major Carter wants to reboot the SGC's network, formatting drives and rebooting from the unnetworked backups from the day before, everything seems to be normal again. Only a minute later, a section is detected infested by the program/being, which had stored itself on the drive of a MALP. When SG-1 break their way into the MALP-room, the entity has used the MALP, then other machines and all computers in the room to build a supercomputer. It runs on the battery powering the emergency lights in the room.

Daniel Jackson argues instead of destroying the machine as O'Neill suggests, they should use the interface it provided (a keyboard and monitor). Carter asks the entity what it wants, and after a reply from the machine, an electric current runs from the keyboard to her fingers. She faints and is brought to the infirmary. Finally, through Carter, the entity is able to communicate its intentions: to destroy the threat Earth poses to its homeworld. SG-1 finds out that when the SGC had sent a MALP to the world, the Earth radio equipment needed to control their robot interfered with the aliens on the world, destroying many of them. Interpreting the action as an attack, the alien entity was sent to infiltrate the SGC's computer system and destroy the facility. While matter can only travel the way a gate was dialed, the entity, like radio waves, could use the radio carrier wave to get into the computer (though when the gate was shut down, it had not had time to complete the total destruction it intended).

Angered with the fact that it uses Carter as host, O'Neill tells the alien that if it stays in Carter's body, the SGC would send wave after wave of MALPs to his planet unless it gave Carter back. In agony, Carter's body breaks free from the restraints it was put in, is trapped in the hall and (picture) emits an energy beam to the mainframe (via the lights and power outlets in the hall). O'Neill zat's Carter's body once but it does nothing. O'Neill is forced to zat her again (which should kill her). Carter falls to the floor. In the medical room Carter is on life support with O'Neill sitting watching over her. Dr. Frasier comes in and asks if Sam ever told him about her living will (that she doesn't want any extraordinary means) to which he replies, "Yeah, she told me." Dr. Frasier tells O'Neill there is no brain activity of any kind and that "I think it's time to let her go." O'Neill quietly asks Dr. Frasier to "wait a minute, huh?" Back in the MALP room, SG-1 sees "I AM HERE" written again and again on the screen. They realize it might be Carter, and Dr. Fraiser connects Carter's body to the supercomputer. Immediately a power surge enters the body, and the supercomputer shuts down. Carter's consciousness, restrained while the entity was in her body, is now returned to her body, and she is soon conscious again. Hammond orders the planet locked out of the dialing computer.

Notable Quotes
Immediately after sending the MALP through the gate

O'Neill: (to Teal'c) You look tense.

Jackson: No, I'd say anxious.

Teal'c: I am neither tense, nor anxious, perhaps concerned.

Jackson: Why?

Teal'c: The address of this planet was procured from the repository of the Ancients.

Frasier: Some form of energy came through the stargate. Its only prudent to make sure there's no physiological effects to those exposed. ASAP.

O'Neill: Who put her in charge?

Hammond: The US Air force.

Teal'c: In medical matters Doctor Frasier may overrule those of any rank.

O'Neill: ( To Daniel) I'm not getting all my memos!

(O'Neill is dancing back and forth in front of a security camera being controlled by the alien Entity in the computer system)

O'Neill: I think it likes me!