when things become more complicated or interesting
TRANSLATION
the plot thickens = wenn sich die Handlung verdichtet, wenn die Geschichte wird noch komplizierter wird, wenn die Sache langsam interessant wird
---
GOOGLE INDEX
approximately 527,000 Google hits
STATISTICS
IN THE PRESS
THE PLOT THICKENS: 'Downton Abbey' studio denies report that Dame Maggie Smith is leaving.
BBC News
Did you know?
the plot thickens idiom
- when things become more complicated or interesting (McGraw-Hill Dictionary)
Apart from being a small piece of land for use as a gardening area or for building a house on (They are building a new house on that plot of land over there), "plot" has other meanings, both as a noun and a verb.
In one sense, it refers to a plan, especially for doing something evil, a conspiracy (The plot to assassinate the president was conceived months ago).
Or if you plot something out, you map it out or make a plan (They plotted out their plans for a new strategy). To plot against means to make a scheme against someone or something (He was fired after they discovered he was plotting against his supervisor).
You can also plot with someone, which refers to dishonestly scheming with someone (He plotted with an investment group to take over the company).
A plot also refers to the story of a play, movie or novel (The play has a very simple plot), and this is where the phrase "the plot thickens" derives from, with thickens meaning to become complicated. The idea is that as a story unfolds in a play or book, the storyline usually becomes increasingly complex, thrilling and/or exciting as more and more information is being learned by the reader or the viewer.