The story takes place in Johannesburg, South Africa in 2016. In response to rising crime rates, a large weapons company developed an all-mechanical police force. They mass-produced and put mechanical police into use, achieving remarkable results in combating crime. As one of the developers, programmer Dean (Dave Patel Dev Patel) has been working on building fully artificial intelligence robots. Until one day, his research made a breakthrough, but he did not receive the support of his boss Michelle Bradley (Sigourney Weaver). Unwilling to fail, Dean secretly took out a mechanical policeman that had been damaged not long ago and prepared to improve his research. Unexpectedly, he was hijacked by three bandits halfway. Under the threat of the bandits, Dean wrote number 22 into a new system. No. 22 was reborn under the name of "Chapai", and its birth will soon change the destiny of many people...