When twenty-one-year-old social media star Chelsea Dawson disappears, Seneca, Maddox, Aerin, and Madison, noticing that she looks exactly like Aerin's murdered sister, Helena, investigate, determined to find the connection.

In an alternative world in which every human being is accompanied by an animal familiar, the disappearance of several children prompts Lyra and her bear protector to undertake a journey to the frozen Arctic in pursuit of kidnappers.

When Artemis learns that his father has been kidnapped by the Russian mob, he races to the Arctic Circle to make a daring rescue, where he finds an old acquaintance, Captain Holly Short, who is investigating a plot of the goblin mob.