Justice, dissenting.
I respectfully dissent. The principal opinion holds that proposed instructions 7E and 7H are inaccurate because neither instruction requires the jury to find that Clark’s specific act of carrying a loaded pistol in his luggage was committed in furtherance of Union Pacific’s interests. The conduct at issue is not the specific negligent act of carrying a loaded gun to work. The conduct at issue is Clark’s failure to warn Cluck of the danger posed by the gun while both were performing a work-related task. Therefore, I would hold that proposed instructions 7E and 7H accurately state the law of respondeat superior liability.
*35As the principal opinion notes, the course and scope of employment is a test of whether “the conduct” of an employee is “performed in furtherance of the employer’s business.” Stanley v. City of Independence, 995 S.W.2d 485, 487 (Mo. banc 1999). The principal opinion identifies “the conduct” at issue as Clark’s specific negligent act of carrying a loaded pistol in his luggage. By identifying “the conduct” at issue as the specific act of carrying a loaded gun, the principal opinion reaches the conclusion that Cluck’s proposed instructions improperly recast the “course and scope of employment” test as a purely temporal test. The logic of this conclusion is sound, but it is based on the incorrect premise that the course and scope of employment analysis looks solely at whether the specific negligent act that caused the injury was an action that actually furthered the employer’s interests. There are two central problems with this premise.
First, defining “the conduct” at issue as the specific negligent act of carrying a loaded gun to work is inconsistent with the analysis of respondeat superior liability. The analysis of respondeat superior liability explicitly recognizes that actions occur in a context. For purposes of respondeat superior liability, the relevant context is whether the injury causing conduct was undertaken in the course and scope of employment. To determine whether an injury causing act was performed in the course and scope of employment, the act must have been “done by virtue of employment and in furtherance of the business interest of the employer.” Daugherty v. Allee’s Sports Bar & Grill, 260 S.W.3d 869, 873 (Mo.App.2008). The course and scope of employment test, therefore, requires an assessment of the context in which the injury causing conduct occurred. Even though a specific act of negligence is what caused the injury, liability is premised on whether that act was performed within the context of “course and scope” of employment aimed at furthering the employer’s business interests. If, on the other hand, the entire course and scope of employment analysis is distilled into an assessment of whether a contextually isolated, specific act of negligence furthered the employer’s business, then respondeat superior liability is effectively abolished except for the occasional case in which a supervisor assaults a subordinate in order to enforce a work order or orders that a work-related task be performed in an unreasonably dangerous manner. If that were the case, employers would be free to reap the benefits of their employees’ labor while avoiding liability for most injuries sustained during the course of that labor.
Second, the principal opinion asserts that Lavender v. Illinois Central Railroad Co., 358 Mo. 1160, 219 S.W.2d 353 (1949), is directly on point and demonstrates that course and scope of employment test looks at Clark’s specific act of carrying a loaded gun in his luggage.1 In Lavender, the employer was not hable because the gunshot was a result of “horseplay” that was wholly unrelated to the performance of a work-related task. Id. at 358. The gunshot occurred while the employees were freelancing their time and, by definition, undertaking no actions in the furtherance of the railroad’s business. In contrast, Cluck was injured while he and Clark were unloading luggage on a business trip. It *36was during the course of this work-related activity, indisputably performed in furtherance of Union Pacific’s business, that Clark was injured. Lavender is inappo-site.
Instead of focusing on the specific negligent act of bringing a loaded gun to work, the focus should be on whether Cluck’s injury was caused by a negligent act that was committed as part of a general course of conduct aimed at furthering the employer’s interests. Under this standard, Cluck’s proposed instructions are sufficient. Although the principal opinion states that the negligent conduct at issue is Clark’s act of carrying a loaded pistol, the theory of liability posited in instructions 7E and 7H was that Clark “failed to warn” Cluck of a loaded gun in the luggage. Both instructions require the jury to find that Clark’s failure to warn was an act committed while Clark otherwise was acting in the course and scope of his employment. Instructions 7E and 7H accurately state the law with respect to vicarious liability in a FELA claim when the course and scope of employment is disputed.
“[A] party is entitled to an instruction upon any theory supported by the evidence.” Vandergriff v. Mo. Pac. R.R., 769 S.W.2d 99, 104 (Mo. banc 1989) (quoting Hopkins v. Goose Creek Land Co., Inc., 673 S.W.2d 465, 467 (Mo.App.1984)). There is no dispute that Clark stored the gun in his luggage on a work-related trip and that he failed to warn Clark of the gun as they unloaded the luggage on that work-related trip. Cluck was injured because Clark failed to warn him of a negligently created, dangerous aspect of a work-related task. Cluck’s proposed instructions accurately stated the law and are supported by the evidence. The circuit court erred in failing to instruct the jury on Cluck’s elected theory of vicarious liability as set forth in Instruction 7E or Instruction 7H. Cluck was- prejudiced by this error because he was deprived of the opportunity to submit his case to the jury on a vicarious liability theory that is supported by the evidence. I would reverse the judgment and remand for a new trial.
. The principal opinion also cites Reeve v. Northern Pacific Railway Co., 82 Wash. 268, 144 P. 63 (1914), and Copeland v. St. Louis-San Francisco Ry. Co., 291 F.2d 119, 121-22 (10th Cir.1961). Like Lavender, Reeve and Copeland were "horseplay" cases in which the employees were engaged in a course of conduct that had no conceivable relationship to the employer's business.