An unbeatable team of five teenage friends, the Peppercorns, unites to find out who is behind the kidnapping of a missing oceanographer who has discovered a means of getting rid of plastic waste in the ocean.

After a break-in at the North Irish oceanographic facility where Tarun's mother Jaswinder Singh works at an invention to reduce the plastic waste mountain floating at sea, she goes missing, like key experimental results. Tarun mobilizes the four fellow peppercorns, who soon help identify the enemy: waste industry captain Robert Fleckmann, whose goons abducted the research vessel to a small harbor in Wesemünde, Mecklenburg-Vorpommern. They demand the priceless invention as ransom for Jaswinder, but Tarun realizes the heirloom pendant she confided to him recently holds the key: clues to the cave hiding place. Plans to save both those and her are crossed by a traitor.—KGF Vissers