Teck v. Pakootas revisits the infamous Trail smelter, which made history in public international law. This more recent case should be set to make history as well, due to the manner in which the issue of extraterritorial exercise of jurisdiction was handled. The substantive result reached in the course seems fair, reasonable and appropriate: a notorious polluter, Teck Cominco Metals Inc., is called to account by the United States Environmental Protection Agency and required to study the feasibility of cleaning up a site it contaminated by dumping effluents in a transboundary river over the course of several decades. Yet both courts that examined this case on the merits failed to understand the ramifications of this extension of the EPA’s jurisdiction across the Canada-US border. This article begins with a doctrinal analysis of jurisdictional rules in private and public international law, and then proceeds to evaluate those rules with the help of insights from scholarship on global administrative law and international public authority.