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Microdots: The CIA's Tiny Secret-Message Holders

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Microdots: The CIA's Tiny Secret-Message Holders

Short | 02:20

In 1971, the CIA sent coded messages to the Hanoi Hilton's prisoners of war through powdered-drink packages. How they hid these cryptic messages was quite ingenious.

More About This show

In 1973, 591 American POWs returned home from the Vietnam War, bringing with them harrowing tales of survival. But there was an even more remarkable -- and secret -- story to tell: a feat of incredible spycraft that remained classified for decades...until now. This is the unbelievable story of James Stockdale and his fellow prisoners at the notorious "Hanoi Hilton." Their clandestine communications with U.S. intelligence alerted the CIA and Pentagon to the horrors of the Vietnamese POW camps and prompted a daring, top-secret rescue mission.


  • Spence Dry
  • Robert W. Wallace
  • Red McDaniel
  • Danny E. Glenn
  • James Bond Stockdale
  • Moki Martin
  • Dr. James B. Stockdale II
  • Michael Mullen
  • Sybil Stockdale
  • Spence Dry

    Spence Dry

    Read Full Bio

    Lieutenant Melvin Spence Dry was the U.S. Navy SEAL commander in charge of the small SEAL-UDT platoon assigned to Operation Thunderhead, a daring mission put in place to rescue two escaped U.S. POWs from a Vietnamese prison camp.

    On June 5, 1972, Dry was accidentally killed in the course of the operation, thereby becoming the last Navy SEAL lost during the Vietnam War. Due to the clandestine nature of the mission, details of his death were long shrouded in secrecy. A campaign to uncover the facts about Dry's death was conducted by his own father, Captain Melvin H. Dry, U.S. Navy, who devoted the next 25 years of his life pursuing the facts and urging the Navy to honor his son's sacrifice.

    In December 2004, the Naval Academy Foundation confirmed that Spence Dry would be recognized as an operational loss during the Vietnam War. Subsequently, in 2008, the Navy awarded Dry a posthumous Bronze Star Medal with Combat "V" for valor for his heroic achievement in leading his platoon in combat operations.

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