The Legend of Viking Thunder (Time Keys Book 2), M G Leonard

Sim's Uncle Emmett is missing and on the run from the ruthless Council of Keys.

Sim and his cousin Jeopardy are determined to find him. Their search takes them through a hidden door in time to Viking Norway and a desperate mission across land and sea to stop the legendary Gjallarhorn – said to herald Ragnarök, the end of the world – from falling into the wrong hands. The Legend of Viking Thunder can be read as a stand-alone novel, or enjoyed as part of the thrilling Time Keys series.

Follow Sim and Jeopardy's adventures in the series in Hunt for the Golden Scarab and The Impossible Gladiator.