Marine biologist Johanne is doing research on a fish farm in Vangsnes, a rural community located by the fjord, when she encounters several strange occurrences. Along with the brutal deaths of two local teenagers, all signs point to the deep fjord; can there be more to the depths than the eye can see? At the bottom of the deepest fjord rests a mythical monster as large as a mountain, with a myriad of arms ready to crush and devour anything they can grab.

Ruby Gillman, a sweet and awkward high school student, discovers she's a direct descendant of the warrior kraken queens. The kraken are sworn to protect the oceans of the world against the vain, power-hungry mermaids. Destined to inherit the throne from her commanding grandmother, Ruby must use her newfound powers to protect those she loves most.

Thirty years ago, Ray Reiter witnessed the brutal death of his parents at sea by a strange, octopus-like creature. Now determined to exact revenge, he joins archaeologist Nicole on a perilous high-seas expedition to find a legendary Greek Opal - said to be guarded by the very beast that murdered his family. As they come face to face with the killer Kraken, they must also battle a ruthless crime lord, who will stop at nothing to seize the coveted treasure for himself.