Arnold is back as the future Terminator to help destroy his younger self while helping Sarah Connor take down the creators of Genysis, which is a computer program that takes over the world. Jai Courtney & Emilia Clarke star as Reese & Sarah Connor (Sean Connor's future parents) while Jason Clarke stars as Sean Connor. It's so confusing I can't even begin to understand, but in the end we know what happens. Jai & Emilia have next to zero chemistry. But Arnold was hilarious. I won't spoil how Arnold's real role, but it's a tailor made role.
Check it out. I give it 4 out of 5 stars.