Currently you are able to watch "The Dark Knight" streaming on HBO Go. It is also possible to buy "The Dark Knight" on Apple TV, Google Play Movies as download or rent it on Apple TV, Google Play Movies online.
Batman raises the stakes in his war on crime. With the help of Lt. Jim Gordon and District Attorney Harvey Dent, Batman sets out to dismantle the remaining criminal organizations that plague the streets. The partnership proves to be effective, but they soon find themselves prey to a reign of chaos unleashed by a rising criminal mastermind known to the terrified citizens of Gotham as the Joker.