A boy tells all the reasons a small, fire-breathing dragon would make an excellent pet, and the ways he would take proper care of it if he had one.

The Dragon Masters are still reeling from the desertion of Rori and her fire dragon Vulcan, when Mina, a Dragon Master from the far north, arrives with a problem--King Lars needs a fire dragon to defeat the Ice Giant who has frozen his kingdom; and so the Dragon Masters set out to find Rori and convince her to help.

The dark magic the dragons encountered in their first adventure has made Ana's sun dragon, Kepri, sick and Drake's earth dragon, Worm, teleports the himself, Kepri, and the four young dragon masters far away from the castle in search of a cure--but the threat of the dark magic still remains.

While the rest of his Viking village battles the dragons that attack them every night, Hiccup secretly makes friends with an injured dragon he names Toothless, but when the other Vikings find Toothless, they want to kill him.

Diego is under the spell of the wizard Maldred who wants to control the Naga, an enormous dragon that lives deep within the Earth, and plans to use Diego to steal the two keys necessary for that purpose; the first key is guarded by Argent, the silver dragon, and Jean his dragon master, so Drake, Bo, Carlos, and their dragons travel to Gallia to try and stop the theft and break the spell on Diego.

The Dragon Masters have two tasks: track down the newly hatched Lightning Dragon, and find his destined Dragon Master, a boy named Carlos, and convince him to trust them--but somebody else has dark plans for this particular powerful and wild dragon.

When the king decides to take the dragons to Arkwood to visit Queen Rose, Rori, Drake, and their dragons are left behind--so when the evil wizard Maldred attacks the castle riding a giant four-headed dragon that spits poison, the two young dragon masters and their dragons are forced to defend the castle by themselves.

Miss Lotta Scales, a dragon also known as Miss Lotty the librarian, wants to retire from taking care of the school's library but will not willingly stand by and see her beloved books replaced by computers.

When Drake discovers that his friend and fellow Dragon Master, Bo, is trying to steal the Dragon Stone, he wonders if the dark wizard might be behind it, and he must try to find a way to protect the stone while keeping Bo's family out of danger.

When Danny and Wendell find an injured bat at the neighborhood pool, they take it to Mexico where Danny's cousin, a bat specialist lives, but once there Danny is snatched up by a giant bat monster, and it is up to Wendell to save him.