In June, the Pennsylvania Supreme Court granted an appeal that could radically alter existing state law on corporate liability based on the veil-piercing theory. The case, arising from a dram shop tort action, is poised to test Pennsylvania law's "strong presumption" against piercing the corporate veil. Hoping to recover damages from an affiliated corporation that was not a defendant at trial, the plaintiff in Mortimer v. McCool, was granted an appeal on the basis of the so-called "single business enterprise" or "single entity" theory. See Mortimer v. McCool, Nos. 20 MAL 2020, (Pa. June 22, 2020). Not currently adopted in Pennsylvania, the theory may be applied to allow a plaintiff to reach the assets of one or more affiliated corporations of the debtor when those "corporations share common ownership and are, in reality, operating as a corporate combine." See Miners v. Alpine Equipment, 722 A.2d 691,695 (Pa. Super. 1998). Courts discussing or adopting the enterprise theory have found its rightful target to be corporate entities that have integrated business ownership and assets to achieve a common business purpose. Thus, in an important sense, by operating what is essentially a "single business enterprise" split into multiple affiliated entities (often purely for the sake of avoiding liability), owners of such enterprises open the door for the courts to impose shared liability. In the past, I have written about veil-piercing in Pennsylvania generally, as well as in specific regard to LLCs and the "alter ego" theory. This column addresses the implications of the Mortimer appeal and the "enterprise" theory for Pennsylvania corporate liability law.