About three billions tons of chemical and conventionnal warfare lay in the bottom of the North and Baltic sea. These silent witnesses of both World Wars have become a true threat for the environment. Confined in unstable metal barrels the poisons started spreading in the sea. Only sixteen percents of these deadly substances’s leak would be enough to erradicate any living sea form for centuries, not mentionning shorelines and territorial pollutions within a large spectrum on the continent. How and why were these weapons dumped in the sea and is this massive propagation of highly toxic products evitable ? The Director takes us to the North seas and dives to witness, to bring testimony and defend the cause of our seas’s survival, along with those investigating or participating to solving this disaster. The film also points at the secrecy of local, national and european authorities on the matter, advocating for transparency and actual solutions.