Call of Duty: Black Ops (CoD: BO) is a first person shooter video game developed by Treyarch and was released on April 2010. It is the seventh title in the Call of Duty series. The game follows Alex Mason and Jason Hudson, CIA operatives during the Cold War, and Viktor Reznov fo the Red Army. Their mission is to locate a numbers station which is due to transmit broadcasts to sleeper agents who are bound to use chemical weapons across the United States. Through flashbacks, the agents must trackdown the enemy. The game is set in different countries all over the world including Russia, Cuba, Hongkong, Laos, Vietnam and the Arctic Circle.
The game received generally positive reviews and within 24 hours after released, the game sold more than 5 million copies in the UK and US alone.