Invasive species are reshaping the world's ecosystems, but who's really to blame? Shane wrestles a python, hunts Hawaiian pigs, and gets sucker-punched by a carp to answer the question: in the Age of Humans, how does our species decide what belongs?

Shane discovers why dogs are more than man's best friend – they've been reshaped by evolution into the perfect partner for our species. And just as we've transformed them, dogs have left an unmistakable pawprint on us and the world we both share.