After Jack becomes apprenticed to a Druid bard, he and his little sister Lucy are captured by Viking Berserkers and taken to the home of King Ivar the Boneless and his half-troll queen, leading Jack to undertake a vital quest to Jotunheim, home of the trolls.

Twelve-year-old Sophie Sawyer's first assignment as a Companion is to help Nimue, a young druid, and Emrys the Excellent, Merlin's thirteen-year-old apprentice, protect the Holy Grail from the evil sorceress, Morgana.

"Tucked among the ancient pines of the Ardeep Forest hides the Emerald Enclave, an order of warriors tasked with preserving the natural world. They fight to maintain balance between the forces of the wild and civilization, and in doing so, protect the sanctity of each. Among their order, Doric begins to find power in her differences. But not all her fellow initiates are so capable of new growth, and as her training continues, Doric is forced to confront...