plot thickens, the

the plot thickens

A situation or set of circumstances has become more complex, mysterious, interesting, or difficult to understand. A: "This whole time I presumed he was working for my father, but it turns out my father has never heard of him!" B: "Ooh, the plot thickens!" Now the plot thickens, as police have opened a line of inquiry into the governor's whereabouts on the date of the incident.
See also: plot, thicken

plot thickens, the

Circumstances are becoming very complex or mysterious. Today this term is often used ironically or half-humorously, as in His companion wasn't his wife or his partner-the plot thickens. Originally (1671) it described the plot of a play that was overly intricate, and by the late 1800s it was used for increasingly complex mysteries in detective stories.
See also: plot