There was no error in the denial of the motion by Metcalf for a judgment of nonsuit. Upon such motion, the evidence offered by the plaintiff must be taken to be true and considered in *343the light most favorable to him and evidence offered by the defendant tending to contradict or rebut the plaintiff’s evidence must be disregarded. Bennett v. Young, 266 N.C. 164, 169, 145 S.E. 2d 853, and cases there cited. So interpreted, the plaintiff’s evidence is sufficient to show that the proximate cause of the plaintiff’s injuries was the act of Courtney in undertaking to pass another vehicle proceeding in the same direction when the left side of the highway was not clearly visible and free of oncoming traffic for a sufficient distance ahead to permit him to pass in safety. This, if true, showed a violation of G.S. 20-150 (a) and such evidence was sufficient to require the submission to the jury of the issue of negligence by Courtney. Bondurant v. Mastin, 252 N.C. 190, 113 S.E. 2d 292; Funeral Service v. Coach Lines, 248 N.C. 146, 102 S.E. 2d 816; Cole v. Lumber Co., 230 N.C. 616, 55 S.E. 2d 86. Proof that the automobile was owned by and registered in the name of Metcalf, which is admitted in his answer and in his testimony, is prima facie evidence that it was being operated with his authority and knowledge at the time of the accident, and that Courtney was driving the vehicle within the course and scope of his employment by Metcalf. G.S. 20-71.1. The evidence of Metcalf to the contrary could not be considered upon his motion for judgment of nonsuit. Consequently, there was evidence which would support a verdict that the plaintiff was injured by the negligence of Metcalf and it was proper to submit that issue to the jury. Johnson v. Thompson, 250 N.C. 665, 110 S.E. 2d 306; Travis v. Duckworth, 237 N.C. 471, 75 S.E. 2d 309.
G.S. 20-71.1 does not, however, abrogate the well settled rule of law that mere ownership of an automobile’ does not impose liability upon the owner for injury to another by the negligent operation of the vehicle on the part of a driver, who was not, at the time of the injury, the employee or agent of the owner or who was not, at such time, acting in the course of his employment or agency. The burden of proof continues to rest upon the plaintiff to prove such agency relationship between the driver and the owner at the time of the driver’s negligence which caused the injury. The statute merely creates a rule of evidence. Proof of ownership of the automobile by one not the driver makes out a prima facie case of agency of the driver for the owner at the time of the driver’s negligent act or omission, but it does not compel a verdict against the owner upon the principle of respondeat superior. Chappell v. Dean, 258 N.C. 412, 128 S.E. 2d 830; Osborne v. Gilreath, 241 N.C. 685, 86 S.E. 2d 462.
It is elementary that a principal or employer is not liable for injury due to a negligent act or omission of his agent or employee *344when such agent or employee has departed from the course of his employment and embarked upon a mission or frolic of his own. Travis v. Duckworth, supra, and cases there cited. It is, of course, not sufficient to take the servant out of the course of his employment, and thus to relieve the employer from responsibility for the negligent act or omission of the servant, that the servant at the time of such act or omission was violating an instruction or rule of the employer or principal. West v. Woolworth Co., 215 N.C. 211, 1 S.E. 2d 546. The test is whether the employee or agent was, at the time of the negligent act or omission, about his master's business. If there has been a total departure from the course of the master’s business, the employer or principal is not liable for the negligent act or omission of the employee during such departure from the employment relation. Hinson v. Chemical Corp., 230 N.C. 476, 53 S.E. 2d 448.
The testimony of both Metcalf and Courtney is that Courtney was requested, i.e., “employed,” to drive Metcalf’s automobile to the home of Anderson in Rutherford County for the sole purpose of transporting Anderson thereto and returning the automobile promptly to the home of Metcalf, and that Courtney, after taking Anderson to his home, proceeded to drive the automobile here and there for his own personal enjoyment for some six hours beyond the time when he had been directed to bring it back to Metcalf’s residence. The plaintiff offered no testimony to the contrary. He relies solely upon the provision of the statute insofar as proof of the agency relationship between Cou*rtney and Metcalf is concerned.
If it be assumed from the fact that, at the time of the accident, Courtney was headed back toward Morganton, and thus toward the residence of Metcalf, the mere turning back in the direction of the course of his employment does not return the employee to the master-servant relationship so as to impose liability upon the employer for the employee’s act or omission. Hinson v. Chemical Corp., supra; Parrott v. Kantor, 216 N.C. 584, 6 S.E. 2d 40.
Thus, the undisputed evidence tends to show that at the time of the negligent driving by Courtney, which was the proximate cause of the injury to the plaintiff, Courtney had stepped aside from the course of his employment. Upon this evidence, Metcalf was entitled to have the court instruct the jury that if they believed the evidence and found the facts to be as all the evidence tended to show, that is, that Courtney was on a mission of his own, they should answer the issue as to whether the plaintiff was injured by the negligence of Metcalf “No.” Chappell v. Dean, supra; Whiteside v. McCarson, 250 N.C. 673, 110 S.E. 2d 295. The failure of the court be*345low to give such instruction, even without a request therefor, was prejudicial error as to Metcalf and for that reason there must be a new trial upon the second issue, which reads, “Was the plaintiff Howard J. Duckworth injured by the negligence of the defendant James P. Metcalf, as alleged in the complaint?” The appropriate instructions upon such new trial must, of course, depend upon the evidence introduced at that trial.