Wyvern

When the King Gareth dies, his potential heirs, twin grandchildren who possess the dragon’s unique strengths, use their inherited powers against each other to vie for the throne. When Drago’s source of power – known as the Heartfire – is stolen, more than the throne is at stake; the siblings must end their rivalry with swords and sorcery or the kingdom may fall.

An alien similar to Ra appears out of the Stargate, killing five soldiers and kidnapping another, a year after the original Stargate mission. A new team is assembled, including some old members, and they go in search of the missing soldier in order to find out how Ra could still be alive. Meanwhile, the alien Goa'uld kidnap Sha're and Skaara, implanting them with symbiotes and making them Goa'uld hosts.

On the rugged isle of Berk, where Vikings and dragons have been bitter enemies for generations, Hiccup stands apart, defying centuries of tradition when he befriends Toothless, a feared Night Fury dragon. Their unlikely bond reveals the true nature of dragons, challenging the very foundations of Viking society.

Ba'al travels back in time and prevents the Stargate program from being started. SG-1 must somehow restore history.