As the son of a Viking leader on the cusp of manhood, shy Hiccup Horrendous Haddock III faces a rite of passage: he must kill a dragon to prove his warrior mettle. But after downing a feared dragon, he realizes that he no longer wants to destroy it, and instead befriends the beast – which he names Toothless – much to the chagrin of his warrior father.

Five years after uniting the dragons and Vikings of Berk, Hiccup and Toothless soar beyond their homeland, charting the vast unknown. During one of their adventures, the pair discover a secret cave that houses hundreds of wild dragons -- and a mysterious dragon rider with a startling connection to Hiccup. And as the ruthless dragon conqueror Drago Bludvist rises to seize control of both dragons and people alike, Hiccup must step into his role as a true leader and, alongside his friends and Toothless, protect Berk from a devastating war.

A man becomes obsessively jealous of his pianist wife and her violinist companion.