In 1989, the British parliament passed The Official Secrets Act, which made it illegal for anyone in the intelligence services or a government contractor to reveal memos of other orders that had been deemed Secret or Confidential. In 2003, Katherine Gun broke that law.

At the time, she worked at GCHQ — the British agency that gathered and sorted through intelligence gathered around the world — where she translated documents and wiretap audio. One day, Katherine and all her colleagues get a memo from a higher up telling them to listen in on the private phone calls of the diplomats from the nations that made up the UN Security Council. The hope was to catch someone doing something that would open them up to being blackmailed into voting for the invasion of Iraq that the Bush administration was pushing for relentlessly.

Shocked by the memo’s contents, she made a copy surreptitiously and passed it to an anti-war activist friend, who gave it to a reporter for The Observer. That newspaper’s editors were staunchly pro-war, but the reporter convinced them to publish the memo nonetheless. When they did, GCHQ turned itself inside out to find who had leaked it, with pressure put on everyone including Katherine, who finally confessed.

When asked why she’d done it, she claimed it was the only way she could think of to stop the war. As we know from history, she failed, as Colin Powell gave a bullshit speech to the UN as part of the the Bush/Cheney propaganda push, British PM Tony Blair and others fell in line, and the disastrous Shock And Awe campaign began a cycle of war that continues to this day, without us once being “greeted as liberators” by anyone.

Keira Knightley plays it very straight as Katherine, but her part of the plot turns out to be the least interesting. Far more compelling are Matt Smith as the reporter and particularly Ralph Fiennes as Ben Emmerson, a civil rights attorney who takes her case pro bono. His argument on her behalf was unusual and led to a satisfying finale.

Gavin Hood, who directed and co-wrote “Official Secrets,” also helmed a Wolverine movie, but there are no special effects to rely on this time. This is a very human story, more closely related to another political thriller of his, “Eye In The Sky.”

Unfortunately, not enough people saw that movie, and I wonder what kind of audience this might attract. Those drawn by its star, expecting a Keira Knightley romcom or period drama, are likely to be disappointed. But if, like me, you’d like to learn a whistleblower’s story you probably knew nothing about, “Official Secrets” is a tightly wound saga about a woman who tried — and failed — to stop the march to war.

I give it a 7.5 out of 10.