12 Chapter adventure/police Serial Cliffhanger
G-Men Never Forget is a 1948 Republic movie serial with 12 chapters.
text from wikipedia
Escaped criminal Victor Murkland (Roy Barcroft) kidnaps the police commissioner and, with the aid of plastic surgery, takes his place. Federal Agent Ted O'Hara (Clayton Moore) is called in to try to stop the wave of crime initiated by Murkland, not knowing that Murkland is posing as the police commissioner and is aware of O'Haras' every move. The real commissioner is being held captive in a mental hospital run by Dr. Benson (Stanley Price). O'Hara is aided by the beautiful Sgt. Francis Blake (Ramsay Ames). Murkland's gang threatens to destroy a major tunnel being built underneath a channel, and blackmails the builder into paying him protection money.
Cast:
Clayton Moore as Agent Ted O'Hara
Roy Barcroft as Victor Murkland/Commissioner Angus Cameron
Ramsay Ames as Frances Blake
Stanley Price as 'Doc' Benson
text from wikipedia
Date of release: 1948, believed to have entered the public domain: Jan 1, 1971
G-Men Never Forget Chapter 01: Death Rides the Torrent
G-Men Never Forget Chapter 02: 100,000 Volts
G-Men Never Forget Chapter 03: Code Six-Four-Five
G-Men Never Forget Chapter 04: Shipyard Saboteurs
G-Men Never Forget Chapter 05: The Dead Man Speaks
G-Men Never Forget Chapter 06: Marked Evidence
G-Men Never Forget Chapter 07: Hot Cargo
G-Men Never Forget Chapter 08: The Fatal Letter
G-Men Never Forget Chapter 09: The Death Wind
G-Men Never Forget Chapter 10: The Innocent Victim
G-Men Never Forget Chapter 11: Counter-Plot
G-Men Never Forget Chapter 12: Exposed