The Sigma Protocol

  • by Robert Ludlum
  • Narrated by Paul Michael
  • 19 hrs and 20 mins
  • Unabridged Audiobook

Publisher's Summary

Do you think you know what really happened after World War II? You don't. Sigma made sure of that. American investment banker Ben Hartman arrives in Zurich, the first time he's been back to Switzerland since his twin brother died there in a tragic accident four years ago. But when Ben chances upon Jimmy Cavanaugh, an old college friend, Cavanaugh draws a gun and tries to kill him. In minutes, several innocent bystanders are dead, as well as Cavanaugh, and Ben is on the run, plunged into an unspeakable nightmare. U.S. Department of Justice field agent Anna Navarro is being stalked by a relentless killer, managing to survive only by a combination of luck, skill, and her own quick wits. The attacks on her are somehow related to her current assignment: investigating the sudden, seemingly unrelated deaths of a number of very old men around the world. The only thing that connects them is an ancient CIA file bearing the code word Sigma. Brought together by accident, Ben and Anna realize that their only hope of survival lies with each other. Together they race to uncover the long-hidden diabolical secrets of Sigma - secrets that threaten everything they think they know, everything they believed about their friends and families, everything they were taught about history itself. For behind Sigma lies a vast deception that is finally coming to fruition - and the fate of the world is in their hands.


What the Critics Say

"Ludlum's trademark skills of intricate plotting, breakneck pacing, and high-wire drama are all on display in this gripping thriller." (
"A memorable swan song." (Booklist)


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Customer Reviews

Most Helpful

Good story until the far fetched ending

I loved listening to this story. It grabbed me from the very beginning and kept me hooked all the way until almost the end. The plot was almost believable and conspiracy types might have even thought Ludlum was on to something. The plot spiraled down to a far-fetched and unbelievable ending however and ruined an otherwise excellent listening experience.
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- Dan

I couldn't put down my player!

Once I got started, I found excuses to pick up my audible player and continue the drama: I was getting up at 5 am to ride my exercise bike (which I rarely do) and listen. I was ignoring the morning radio news during my commute to listen. I took a long walks on the weekend to listen. When it was over, I was happy I had my life back.
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- Michael H.

Book Details

  • Release Date: 10-19-2001
  • Publisher: Macmillan Audio