As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN - FLT 1320 - IMMEDIATELY AFTER TAKEOFF DEN SMOKE AND FUMES ENTERED THE CABIN, AIR INTERRUPTED BACK TO DEN AND LANDED WITHOUT INCIDENT. TIGHTENED NR 2 ENGINE THRUST REVERSER BYPASS VALVE B-NUT. CLEANED OUT RESIDUAL HYDRAULIC FLUID IN APU. CHANGED COALESCER BAGS. ACCOMPLISHED PACK BURNOUT. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)