Ancient Runes
Status
Summary
The full moon has been proved to have a certain effect on dragons, making aggressive ones calm and vice versa. However, Toothless hasn't shown much reaction to the full moon. But, on the eve of the rare blue moon, Toothless begins to act strangely and Hiccup decides to figure out what is wrong. (Takes place not long after the events of HTTYD 2. Contains spoilers.)