Michael's health club is beseiged with a series of terrible murders involving killer saunas and other grisly devices. Michael's wife killed herself a while before and her brother holds Michael responsible. Michael needs to stop the bloodshed before he loses all of his clients.

The special bond that develops between plus-sized inflatable robot Baymax, and prodigy Hiro Hamada, who team up with a group of friends to form a band of high-tech heroes.