What is the author's style in The Mousetrap by Agatha Christie?

The Mousetrap is a two-act play. The exposition, complication, and climax are combined in the first act with the story of the child's murder and the murder in London and in the final minutes of act one when Mrs. Boyle is murdered. The falling action and catastrophe are combined in the second act with the realization that a murderer is in the house and that Trotter is Georgie.