Terminator Genisys starts in 2029, with the end of the rebellion against Skynet HQ, which makes it, essentially, both a prequel and a sequel to The Terminator, as we see the T-800 played by Schwarzenegger go back to 1984 and try to assassinate Sarah Connor, to make sure her son, John, will never be born, and therefore, not be able to lead humanity to victory against the machines. Following not long behind to keep this from happening is Kyle Reese, who soon discovers that he and the the killer cyborg aren't the first ones to travel to the past in this timeline, as he is soon met by an older form of a T-800 that was sent even further into the past to serve as Sarah's protector (earning him the nickname, "Pops"), as well as an even more dangerous T-1000 out to take them all down. Sarah, who is fully aware from an early age on what to expect will happen in the year 1984, barely needs protecting, and might only be interested in keeping Reese around because he is also needed to create John in the future. Together, they seek to keep the Terminators from killing the seed of Resistance in Earth's future, while the humans seek to stop the creation of Genisys, the seed of what will eventually become Skynet -- it's a race against time through time.