Anthills of the Savannah is about three friends trying to live under an oppressive military regime.
The three friends who are the focus of the story are Sam, the president of Kangan; Chris, the Commissioner of Information for Kangan who dates Beatrice, the Minister of Finance; and Ikem, the editor of The National Gazette who is dating Elewa, his pregnant girlfriend. They don't all agree about the direction and methods of Kangan.
Sam has changed as he's ascended to power. In the past, his friends thought he'd be a good president. However, power makes him hungry for more power and more oppressive of the people. He's willing to put down resistance with force, if necessary.
Ikem, on the other hand, is having a more difficult time coping with the power the friends have gained. He uses the paper to criticize the government even though technically the paper is working for the government.
Chris thinks things can be maintained if they just hold the power and make Sam less radical. He tries to convince Ikem to work with him rather than against him. Ultimately, Ikem is fired from the paper, speaks out against the government, and is killed by the state police when people say Ikem wants Sam beheaded. It was just a joke about coins that they're referring to, however.
Chris tries to flee when they want to arrest him and he does get out of the city. Sam is killed by another group taking over his government in response to his lack of popularity, paranoia, and bad choices. Chris is killed defending a woman he met while he was attempting to get away from Kangan. Ultimately, Beatrice holds a ceremony to name Elewa and Ikem's daughter after she finds out that Chris has died.