Answering the question before us "is not a simple, straightforward exercise," Henderson v. Central Tel. Co., 233 Va. 377, 382, 355 S.E.2d 596, 599 (1987) ; it "depends upon the facts and circumstances of the particular case [and] ‘does not readily yield to categorical or absolute standards.’ " Johnson v. Jefferson Nat'l Bank, 244 Va. 482, 485, 422 S.E.2d 778, 780 (1992) (quoting Bassett Furniture Indus., Inc. v. McReynolds, 216 Va. 897, 902, 224 S.E.2d 323, 326 (1976) ). The Act's exclusivity provision, Code § 65.2–307(A), mandates that the rights and remedies provided in the Act "exclude all other rights and remedies" of a covered employee or his beneficiaries for injuries sustained in the course of employment.