This "clicker case" is based on the General Biology edition of James Hewlett’s “Bad Fish” case in our collection. The case follows the story of biologist Dr. Westwood, who is accidentally poisoned, first while traveling in Asia and then in the South Pacific. Students learn about Dr. Westwood’s experiences and about nerve cell physiology—focusing especially on the role of ion channels in maintaining and changing electrical gradients across the cell membrane (resting potential and action potentials). They then apply what they learn in each part of the case to determine the mechanism of neurotoxin poisonings described in the case. The case is presented in class via PowerPoint (~2MB).  Students use personal response systems, or “clickers,” to answer the multiple-choice questions that punctuate the PowerPoint presentation as they explore the underlying mechanism of Dr. Westwood’s poisoning.