In Mexico City, a newly modified liquid Terminator -- the Rev-9 model -- arrives from the future to kill a young factory worker named Dani Ramos. Also sent back in time is Grace, a hybrid cyborg human who must protect Ramos from the seemingly indestructible robotic assassin. But the two women soon find some much-needed help from a pair of unexpected allies -- seasoned warrior Sarah Connor and the T-800 Terminator.