The Evil Code Under Lanzhou Tower

The three seemingly unrelated cases (the death of an antique dealer in a secret room, the disappearance of a female college student, and the "suicide" of an old policeman) have different symbols left at the scene (bronze bird pattern, encrypted QR code, and the handwritten word "Guixu"). In fact, they point to the same unjust case of the "Seven Sons of Lanzhou" that spanned 30 years. Five of the seven suspects died in an "accident" and two disappeared. Now the relevant persons in the case are being silenced one by one. All clues must pass "three lines of verification" - physical evidence (antiques, old files, experimental samples), witness memories (elderly residents, retired police officers, family members of the case), and digital traces (dark web records, old computer data, surveillance backups) to be established. Any single clue may be forged.