Sam, Daniel and Teal'c are under attack from a large number of Jaffa. Jack and another man called Lt. Tyler are pinned down and can't get to the others, Jack tells them to leave them there and get off the planet. Arriving at the SGC they tell Hammond what is happening, but Hammond has no idea who Lt. Tyler is. Hammond orders SG-1 to the infirmary.

On the alien world, P75-441, Jack and Tyler get to safety in an old building. At the SGC Hammond removes 441 from the active planets list, no one can go back there till they sort out what is going on. In the room that Daniel, Sam and Teal'c have been placed in they talk about what is going on, they do not know what to believe and search the bases computer for info on Tyler, they find nothing but Sam finds someone else has been accessing the bases computer.

On 441 Jack goes to look for water, as he leaves there are some rations in a bag near Tyler, written on them are Tyler and made in Texas. The SGC have launched a UAV to 441 and contact Jack, he tells them he and Tyler are alright, Hammond now knows Jack is affected as well. A second UAV is suggested when they loose contact with the first but Col. Simmons turns up and tells them not to bother. Simmons is here to investigate what is going on, Hammond is not happy.

Simmons starts to interview SG-1, starting with Daniel. Simmons asks Daniel about his ex girlfriend being a Goa'uld and the fact his wife used to be and it could make Daniel sympathetic to them. In the Infirmary Dr Frasier finds some residue on Teal'c's jacket, after she has touched it she sees Tyler. She goes to see Sam who tells her to find evidence before she says anything to anyone else. Hammond meanwhile starts making phone calls about Simmons, he wants to know who he works for.

On 441 it is night time and Jack and Tyler talk about themselves, Tyler tells Jack he is from Texas but has moved around a bit, Jack tells him that the next day they will head into the hills until the Jaffa loose interest in them.

At the SGC Simmons is grilling Teal'c about his recent defection to Apophis, Teal'c tells him that he is no longer a threat.

The next morning on 441 a Glider passes over Jack and Tyler's position, Jack manages to shoot it down. Jack starts placing charges and making a defensive position, they will have to stay here as Tyler is still injured and the Glider has made their position.

Sam is now being interviewed by Simmons, he says he thinks she is going potty and is too friendly to aliens, Sam points out it was Simmons who was looking at restricted files and he ends the interview when Sam really starts to push him about it.

Back on 441 Tyler tells Jack that he can't die protecting him, he tells him he isn't a member of SG-1 but an alien who made them all think he was, but Jack won't leave him. The Jaffa approach their position.

At the SGC Dr Frasier has worked out what is happening and tells Hammond & Simmons what is going on. Against Simmons wishes Hammond send SG-1 back to the planet.

Jack and Tyler come under attack and after a struggle the Jaffa surround them but the others arrive just in time and rescue them.

Going back to the gate they find it guarded by Jaffa. Jack, Sam and Teal'c take a look around and Teal'c recovers the weapon from the downed Glider. Tyler and Daniel have been left together and Tyler zats Daniel and leaves. Jack, Sam and Teal'c arrive back to find Daniel recovering from the zat blast, they watch as Tyler leads the Jaffa away from the gate. The Jaffa capture him.

As they head back toward the gate SG-1 ambush them and rescue Tyler. Tyler returns to his home planet but before he goes Jack tells him that his people don't have to bury the gate, not every race out there is bad like the Goa'uld.