This article proposes a theory' of vicarious liability which attempts to explain the central features and limitations of the doctrine. The main premise of the article is that the common law should continue to impose vicarious liability because it can co-exist with the current tort law regime that imposes liability for fault. The author lays out the central features of the doctrine of vicarious liability and examines why the leading rationales (such as control, compensation, deterrence, loss-spreading, enterprise liability and mixed policy) fail to explain or account for its doctrinal rules. The author offers an indemnity theory for vicarious liability and examines why the current rules of vicarious liability are limited in application to employer-employee relationships and do not extend further. It is proposed that the solution to the puzzle of vicarious liability rests within the contractual relationship between employer-employee and not the relationship between the employer and the tort victim. The proposed indemnity theory implies a contract term that indemnifies the employee for harms suffered in the course of his or her employment. Vicarious liability then follows from an application of the contractual concepts of subrogation and indemnity to the particular relationship between employee, employer and tort victim. Finally, the article discusses and attempts to resolve the possible criticisms that may follow the indemnity theory, including concerns that it is in conflict with leading decisions, including Lister v. Romford. Bazley v. Curry and Morgans v. Launchbury.