As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT 10,000 MSL ON CLIMB THE NUMBER 2 PROPELLER RPM SLOWLY STARTED TO DECREASE. AN ATTEMPT TO FORWARD THE PROPELLER LEVER CAUSED THE RPM DECREASE TO CONTINUE. THE ENGINE WAS SHUT DOWN IN FLIGHT, AN EMERGENCY WAS DECLARED AND THE CREW RETURNED THE AIRCRAFT TO THE DEPARTURE AIRPORT WHERE AN UNEVENTFUL SINGLE ENGINE LANDING WAS MADE. MAINTENANCE TROUBLESHOT THE PROBLEM AND REPLACED THE PROPELLER GOVERNOR. NO FURTHER DEFECTS NOTED.