A mistrial is where a judge effectively cancels a trial because of an extremely prejudicial error that occurs during a trial. “A mistrial is a drastic remedy, and the decision to grant one is largely within the discretion of the trial court.” Callahan v. Cardinal Glennon Hosp., 863 S.W.2d 852, 867 (Mo. 1993); see Pierce v. Platte-Clay Elec. Co-op, Inc., 769 S.W.2d 769, 778 (Mo. 1989) (mistrials are a most drastic remey and should be reserved for the most grievous error where prejudice cannot otherwise be removed). The party requesting a mistrial must establish prejudice and that mistrial is the only sufficient remedy. Id.