Charley manages to save Derek’s life as he flashes back to the final moments of the Future War while recovering. In his flashbacks, we learn that John Connor has sent Derek and Kyle out on a diversionary mission to get them out of danger from their local base, which was going to be attacked by the machines. Kyle manages to evade the machines, but Derek and his team are captured by the terminators and brought to a safehouse to be tortured for information. Eventually the machines leave their safehouse once someone gave out the location of their base.
During his captivity, one of the resistance fighters confides to him that his name is not William Wisher and that he is the one who created Skynet. It turns out that this person is the same Andy Sarah Connor considered killing in the present. Derek keeps slipping in and out of consciousness in the present, but is given a blood transfusion by John to stabilise his condition. Charley starts suspecting that Derek may be John’s father until Sarah assures him that it is someone else.
Derek and his team return to find almost everyone killed, and a burnt picture of Sarah Connor. It is implied that the battle was basically Kyle Reese’s flashback from the first “Terminator” movie where Sarah’s picture gets burned during the battle. Later, they are met by another tech com regiment who brings them to another base. During the process, he is informed that John Connor and Kyle went with a team to destroy a research facility and Kyle became MIA in the process. It is again suggested that John had sent Kyle back in time as shown in the first terminator movie. Once he arrives at the new base, Derek panics when he sees Cameron until he is reassured that it is a reprogrammed terminator, which is a project John initiated to change the tide of war.
Derek also remembers a reprogrammed terminator going rogue and killing several soldiers before it was stopped by Cameron. Finally, he is summoned by John Connor to go back in time with a team and await further instructions. It becomes clear that Derek has intentions of creating a safehouse and killing Andy once he finds him.
In the present, Charley is shown the remains of the deactivated terminator from the last episode and he is clearly frightened but now understand why Sarah and John left him. Cameron then prepares to destroy all traces of the terminator by first extracting the flesh before incinerating the endoskeleton with thermite. Sarah then orders Cameron to find the missing arm from the last battle and to destroy all pieces of the T-888, but Cameron secretly keeps a piece of the T-888’s CPU for some reason.
After stabilising Derek’s condition, Charley bids Sarah farewell but not before informing her that an FBI agent had visited him asking about her. Derek regains consciousness in the present and John informs him that Kyle was sent back to the past to protect him. He also tells him he died a hero. The episode ends by revealing that Derek is in fact the one who killed Andy with previews showing Agent Ellison showing the T-888’s severed hand to a scientist, Sarah finding a tape, and Cameron acting strange.