A Morel Dilemma: Episode 4 — A Familiar Shape

When every obvious test comes back negative, investigators have to look for another way to prove what caused the outbreak. So this episode takes a step sideways, from Bozeman, Montana to a small mountain village in the French Alps, where researchers faced a different kind of mystery: a cluster of ALS cases with no clear cause. What they found there may help explain how scientists can link a…