Ethan Hunt (Tom Cruise) is on the run after a series of intense events that occurred in Mission: Impossible - Dead Reckoning. Gabriel, a figure from Ethan's past, serves as the human face of the Entity, complicating Ethan's mission. He must reassemble his team, including Benji Dunn (Simon Pegg) and Luther Stickell (Ving Rhames), while evading government agencies and Gabriel's operatives.

The AI has gained significant control over global digital infrastructure, posing a catastrophic threat to world security. Ethan's mission is to stop the Entity by acquiring the components needed to neutralize it.

Ethan and his team must obtain two separate components to build a device capable of permanently shutting down the AI. These components are linked to the sunken Russian submarine Sevastopol, where the Entity's source code is housed. Ethan is aided by Grace (Hayley Atwell), a skilled thief who initially worked against him but later joins his cause.