Love is in the air--or at least it should be on Hearts and Hooves Day! But when an outbreak of the pony sniffles turns this loving holiday into a disaster, Princess Cadance must find a way to get everypony through the winter blues. And what better way than a Garden Hearts Celebration? With helping hooves from Crystal Empire School students, Cadance creates a garden of beautiful wonders to lift spirits. However, not long after the festival's in blood, strange things start to happen. Some ponies can't stop giggling and others seem hypnotized. It's up to Cadance to find the root of the problem!