Carnahan wrote World War Z, adapting a novel structured as a series of unrelated oral testimonies into a single continuous investigation. The adaptation is drastic, and what it preserves is the source's central interest: the outbreak is a test of institutions, and most of them fail.
His screenwriting has concentrated on political and procedural material, including a thriller about a military investigation abroad, an adaptation of a British political conspiracy series and a drama about a major industrial disaster at sea. He has also directed a feature of his own, and his work consistently favours process over spectacle.
Recurring subjects: institutional failure, professionals discovering their organisation will not protect them, and crises understood through procedure. His screenplays are structured as investigations, releasing information at a controlled rate, and they resist personalising a systemic problem into a single villain who can be defeated.
His outbreak adaptation became one of the highest grossing films of its genre, and the extent of its departure from the source is a standard case study in what adaptation legitimately permits. His disaster drama is widely praised for its technical accuracy and its refusal of heroic simplification.
For readers interested in adaptation that keeps a theme rather than a structure. Suited to anyone who read the novel and wondered how it could possibly be filmed, and to those who like political thrillers where the procedure is the plot.
