The Plot Thickens

Stock Phrase often said after a turning point in the Plot.

It usually refers to things becoming overly complex or mysterious. Today this term is often Played for Laughs. Coined in the 17th century, it originally 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.

The phrase is sometimes parodied as "The plot sickens". You may also hear "the plot thins" - usually uttered after a major Anticlimax.

Film
"Castor Troy: [looking at Jamie in her underwear] The plot thickens."
 * Face Off.

"C.S. Lewis: He comes; he sleeps; he goes. So the plot thickens."
 * Shadowlands

Literature

 * Famously used in the Sherlock Holmes story A Study in Scarlet, as uttered by Holmes himself.
 * One of the chapters in The Phoenix Guards by Steven Brust is titled "In Which The Plot, Behaving In Much The Same Manner As A Soup To Which Cornstarch Has Been Added, Begins, At Last, To Thicken."

Live Action TV
"Wo Fat: As we clever Chinese say, "The plot thickens...""
 * Hawaii Five-O (1968) pilot episode.

"Michael Knight: So, the plot thickens. I bet this guy David Dalton is not down in Mexico looking for the world's biggest burrito."
 * Knight Rider episode "Mouth of the Snake"

"Pauline: It's about Mickey. He's getting married. Ross: Oh-ho. The plot thickens."
 * The League of Gentlemen

Newspaper Comics

 * Garfield has said this a few times.

Poetry
"Ah ha, you see, the plot grows thicker, And Cindy's luck starts looking sicker."
 * Roald Dahl used this to customary darkly comic effect in his retelling of Cinderella

Video Games

 * Dragon Age Origins: The Warden can say it during one of Leliana's tales.

Western Animation

 * Justice League - When Luthor's soon-to-be Injustice Gang sees who's gathered them, the Shade quips, "Lex Luthor? The plot thins."