The idiom "the plot thickens" was coined in the 1671 satirical play "The Rehearsal" by George Villiers (the second Duke of Buckingham), where it originally used to describe the plot of a play that was overly intricate. By the late 1800s it was used for increasingly complex mysteries in detective stories.
Today, "the plot thickens" is often used ironically or half-humorously to indicate that a situation is becoming more intricate or unexpected.
The phrase is sometimes parodied as "The plot sickens." You may also hear "the plot thins" - usually uttered after a major Anti-Climax.
- online source with editing
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Received an email from a friend yesterday describing a new issue she is facing. The idiom was mentioned in there to express her feeling.
That really got me thinking: the world is a big stage with so many ongoing plots, some big, some small, and some at a personal level. As the Bard of Avon once said: "All the world’s a stage, And all the men and women merely players; ..."
So, I'm sure we all have run into, or have seen, or are watching "the plot thickens" events in our lives and on the world stage. Actually my laptop went for a "nap" when I was writing this APAD and didn't want to wake up, likely to avoid facing the thickened plots. 
Have a good Friday!
