First I present a puzzle involving two opaque objects and a shadow cast on the ground. After I offer a solution to this puzzle by identifying which of the objects is causally responsible for the shadow, I argue that this case poses a counterexample to David Lewis’s latest counterfactual account of causation, known as his in-fluence theory. Along the way, I discuss preemption, overdetermina-tion, absence causation, and trumping preemption.