Terminator Salvation's

After a brief recap of events leading up to Terminator Salvation's present day - post-apocalyptic 2018 - we find Skynet and its Terminators, Hunter-Killers, Hydrobots, and other cruel machines have left the planet a bombed out wasteland, with just scattered pockets of human survivors. Members of the Resistance (they wear red arm bands as a badge of courage) fight off the machines in organized assaults, but we humans are not winning this war.

John Connor, not yet the leader of the Resistance, is disliked by the Resistance's head guy (played by Michael Ironside) but respected by the grunts on the ground. Along with his right-hand man Barnes (Common) and his eight months pregnant wife, Kate (Howard), John Connor works on hunting down Skynet's machines. But an encounter with Marcus Wright completely changes John Connor's perception of Skynet's capabilities.

Marcus is a hybrid with a human heart and brain housed in a skin-clad mechanical body, a creature - apparently of Skynet's making - that Connor never knew existed. Resistance fighter Blair Williams (Bloodgood) trusts Marcus - he saved her life - but the Connors aren't as accepting. Marcus is declared an enemy, Blair has to rescue him from being put to death, and that sets up a confrontation between John and Marcus that changes the course of both men's lives. John and Marcus discover they share a goal: to keep Kyle Reese (Yelchin) alive. Kyle's been captured by Skynet and John Connor knows there is no other option than to rescue him. The future of mankind is depending on it and if it means he has to try and trust a machine, then he's willing to go that far in order to guarantee Kyle's survival.

Source : movies.about.com