The Hyenas of Bangui follows a trio of elite African mercenaries—Chaka, Rafa, and Minuit—who are enlisted to extract the notorious Mexican drug lord Felix from Bissau, Guinea-Bissau, amidst the chaos of a coup d'état in 2003. Their mission promises a hefty reward: a briefcase filled with gold. However, their plans take a dark turn when sabotage leads to a leak in their airplane, forcing an emergency landing in a secluded area of Senegal's Sine-Saloum region.
In search of a safe haven from the authorities and resources to repair their damaged aircraft, Chaka, who hails from Sine-Saloum, guides his crew and Felix to an isolated retreat called the Baobab. He asserts familiarity with the resort and its proprietor, Omar. Unfortunately, the group's ruse of posing as gold miners unravels upon their introduction to Omar’s loyal assistant, Salamane, and the other guests, including the talented Younce, Sephora, and the enigmatic Awa, a deaf and mute woman. Tensions escalate quickly, particularly when Awa discreetly signals to the Hyenas that she recognizes their true identities, demanding to join them, and when the unexpected arrival of Souley, a policeman from Dakar, complicates matters.
As the group dines together the following day, Souley confronts Felix, revealing knowledge of their secret identities and announcing that his team plans to storm the Baobab during the meal. In a shocking turn of events, Chaka confronts Omar, disclosing his traumatic past as a former child soldier under Omar’s command, a warlord previously known as Colonel Remington. Fueled by rage and a desire for revenge, Chaka takes Omar's life with a revolver he once stole from him during his escape as a boy. Just when the tension peaks, it is revealed that Chaka had betrayed the team earlier that day by buying out Souley’s men using Felix's gold.
Chaos erupts when sinister entities emerge, swiftly taking Felix's life. As the remaining survivors seek refuge, Salamane unveils the dark truth: Omar was harboring the curse of Gana Sira Bana, threatening to unleash horrors upon the Sine-Saloum Delta. With these malevolent forces attacking primarily through sound, the survivors must cleverly isolate themselves from external noises, utilizing Awa’s deafness and the Hyenas’ expertise in sign language.
In an act of forgiveness, Rafa and Chaka, accompanied by Souley and Salamane, embark on a journey to a nearby village inhabited by the Sira Bana-worshiping Diola people, seeking methods to shield themselves from sound and the materials necessary for their aircraft. Chaka uncovers the imprisoned children, previously exploited by Omar for his dark rituals. However, tragedy strikes when Souley is claimed by the entities, and Salamane meets a grim fate at the hands of vengeful children previously subjugated by Omar.
As Rafa and Chaka return to the Baobab, they find themselves engulfed in despair with the deaths of Younce and Sephora weighed against Minuit, who, although alive, is now lost to his spiritual affliction. Heartbroken, the two mercenaries grant him a merciful end. They escape by boat with Awa, having procured the necessary resources to repair their plane. Yet, their troubles are far from over—one of the entities, possessing Omar's form, drags Chaka into the depths, asserting its claim over him while Rafa and Awa manage to evade their fate, separated from the malevolent swarm.
