As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUMES - RETURNED TO MSP DUE TO FUMES IN THE FLIGHT DECK. CONFIRMED THAT FLUID LEAKING FROM SEVERAL BOXES OF FISH THAT WERE LOADED IN THE FORWARD CARGO AS THE SOURCE OF THE SMELL. CLEANED CONTAMINATED AREA AND REPLACED CABIN AIR RECIRCULATION FILTERS. (LP 7787562)