Mattes and Melanie respond to robbery alert in fish snack bar "Kallis Kutterklause" which was vandalized and robbed of all seafood. Yet owner Kalli is more secretive then cooperative, being a dodgy petty criminal himself. The sandwich they bring from there to hungry Tariq makes him ill, as turns out due to fish from a batch Kalli stolen from a fishy monger, which also contained smuggled medication. That trails to Dr. Jasmin Jonas's colleague Dr. Evgenji Pawlow, who discretely treats patients without Insurance, and ultimately his supplier Waldemar Rebel, a big fish.
—KGF Vissers