In Peters v. Pima Mercantile Co., 42 Ariz. 454, 27 P.2d 143 (1933) the Court affirmed a ruling as a matter of law that an employee-driver had departed from his employment to such an extent that the employer could not be held vicariously liable for his tortious conduct. In that case, the employer directed his employee to drive from Marana to Tucson to pick up merchandise for the employer's store. Id. at 459, 27 P.2d at 145. The employee drove to Tucson and placed a portion of the merchandise in his truck, but then, without his employer's knowledge or permission, departed to a nearby veterinary hospital to retrieve an animal. Id. After placing the animal in the vehicle, the employee was involved in a collision while returning to pick up the remaining merchandise. Id. Because the employee's deviation from his employer's instructions was "marked and unusual," the court held as a matter of law that the employee was no longer on his employer's business. Id. at 462, 27 P.2d at 146.