Ryan and Kendra have returned to Maple Harbour on the British Columbia coast to visit their cousins Claire and Nathan. But the sleepy little town has been rocked by the news that a valuable Indigenous mask has been stolen, only days after it arrived at the local museum! While museum officials and the police search for answers, the four children and their new friend Tyler stumble upon a series of exciting clues. As they enjoy their summer holidays, not everything is what it seems. Join the four friends on another unforgettable summer of adventure!