After a run-in with a dangerous bull shark in a South American river, the Kratt brothers find a bottle with an old map inside. The map shows the travels of a legendary orca that supposedly specializes in eating large sharks. To find out if the story of the shark-eating orca is true or not, Chris and Martin join a pod of orcas and use the newly upgraded Dolphin Decoder to communicate with them. The Wild Kratts soon discover that orcas are powerful, intelligent predators that can prey on almost any other animal in the sea. But when a great white shark threatens an orca calf, the shark is eaten by none other than Old Sharktooth, the legendary shark-hunting orca!
