No less than the great, spectacular oceans, Europe’s North and Baltic Seas still have intriguing stories to tell and secrets to reveal. The waters between the Kattegat and Darss, between the Ghost Forest in Germany’s Mecklenburg, and Sweden’s largest island are the scene of dramas, both great and small. We see a Gotland grass snake swim out to hunt in the sea - filmed here for the very first time. We witness the first weeks in the life of a baby seal, facing a multitude of challenges. The narrows of the Little Belt are home to a lobster, a rare visitor. To survive here it must overcome several obstacles, from storming currents to rival crustaceans. Meanwhile a male lumpfish desperately protecting his partner’s freshly laid eggs. This series, however, portrays not only the glories of the seas, but also, crucially, their vulnerability.