A MALP is sent through the gate. When it arrives at the other side they see an advanced technological world. Suddenly the MALP starts to fly and then they loose the A/V signal even though it is still transmitting, instead a strange feedback pulse is detected in its place. Hammond orders the gate shut down so they can study the transmission when suddenly an EM pulse hits the computers, they can't shut down the gate. Jack manually overrides the controls and it shuts down.

The EM pulse hits the base.

Sam has received a bad burn and is treated by Dr Frasier. When Sam leaves the infirmary the computer that Frasier used starts to go through her medical files, no one notices. As Daniel and Sam look at the video from the world a CCTV camera behind them starts to move, it turns to observe them. Daniel and Sam go to Hammond and tell him that whatever got into the computers went through software that would teach it to 'read and write'. Behind them the CCTV again observes. In the MALP room one of the MALP's starts to move by itself.

In a briefing they discuss what it could have been. Daniel decides to call it a probe. Dr Frasier tells them that the energy patterns it produces are like an EEG, it may be intelligent. Suddenly the lights go out and the briefing room is shown on the large view screen, the entity must still be here in there computer systems. It access the personnel files to find out who everyone in the room is.

The entity observes everyone in the briefing room.

Hammond orders all the computer systems shut down, as they go one of the MALP's removes an emergency lighting beacon.

On trying to reboot the computer systems they find out that an emergency light is still on in the MALP room. Going to investigate they find the door welded shut and have to cut there way in, inside they find a cobbled together computer system, the entity has created itself a mainframe.

The entity's mainframe.

Jack wants to blow the thing up but Daniel and Sam want to communicate with it. Hammond arrives and is talked into letting Sam try to communicate via the keyboard as the thing can be killed by cutting the emergency power lead to its little nest. Sam starts typing but suddenly freezes, something is passing into her body, Jack cuts the power and Sam collapses.

Doctor Frasier rushes Sam to the infirmary where she flat lines, as they prepare the paddles her pulse comes back. Frasier takes an EEG and finds that the entity is inside Sam.

On Teal'c's suggestion Hammond has Sam placed under guard, they won't be fooled by the entity again. As Jack watches over Sam she awakes and he calls Frasier. The Dr says that she will give 'Sam' a speech translator so the entity can communicate with them.

Sam awakens but the entity really controls her.

Jack speaks to it, it tells him that it had no where else to go, it did this for survival and Sam is important to him, and the others, so they won't terminate her or try to extract it for risk of killing her. Daniel now talks to it and finds out it has come her to destroy us, the MALP we sent through to its world damaged it and they though we were attacking them. Jack tells it that we will send an army of MALP's to its world unless it releases Sam, Daniel is shocked but Hammond concurs, unless it leaves they will do it.

Daniel talks to the entity.

Sam suddenly gets up and rushes off but is cornered. She puts her hands up and energy starts coming out of her, Jack zats her but it does nothing, reluctantly her zats her again, she collapses.

In the infirmary Frasier tells Jack that Sam is brain dead and that she made a will saying she wanted no prolonging of live if this happened, Jack knows but asks for another minute.

In the gate room they start to reboot the computers, at the entity's mainframe a message appears, 'I am here'. Daniel says it must be Sam, the entity transferred her consciousness to the mainframe before Jack killed it, thus Sam would survive and the entity's world wouldn't be attacked. Frasier arrives and does an EEG, the pattern is Sam's, she hooks her up and hopes it will work, energy starts to move into her and she reawakens, Sam is back to normal.

Relief as Sam returns to them.