After nearly 50 years of movies, TV series, and packed convention halls, Star Trek is poised to boldly go where it's never gone before: Into darkness. After months of speculation, Paramount has confirmed that the sequel to J.J. Abrams' hit 2009 reboot of the Star Trek film franchise will be called Star Trek Into Darkness, and will hit theaters on May 17, 2013. With the film's storyline cloaked in mystery, fans and critics are analyzing every morsel of information that escapes from the film's Fort Knox-like set. And now, the unusual title "only raises more questions." What could Star Trek Into Darkness possibly mean? Here, four theories:

1. It's a callback to the plot of Abrams' first Star Trek film
The title "presents an unusual mental picture — are the stars trekking into some unknown darkness?" asks Adam B. Vary at Entertainment Weekly. "For me, the title evokes the black holes and singularities that drove so much of the story in Abrams’ first Trek film, from the time traveling to the destruction of Vulcan." The new title could be a sign that the consequences of the galaxy-altering events in the first Star Trek had greater implications than we thought.

2. It's a reference to the fan-favorite villain Khan
If you're looking for "darkness" in the Star Trek franchise, search no further than "a war on Earth that takes over 30 million lives and almost lands humanity back in the Dark Ages," says Scott Collura at IGN. The genetically-engineered villain Khan (Ricardo Montalbon) was introduced in a 1967 episode of Star Trek as a tyrant who almost took over the Earth during the "Eugenics Wars." If the widespread theory that new cast member Benedict Cumberbatch will be playing Khan turns out to be true, the new title could be an early sign "that the darkness of that time period is somehow carrying over into Kirk's era."

3. It's a nod to Christopher Nolan's Dark Knight trilogy
The filmmakers behind the new Star Trek movies "often point to Christopher Nolan's Batman trilogy as inspiration," says Anthony Pascale at Trek Movie. Nolan surprised fans when he revealed several years ago that the sequel to 2005's Batman Begins would be called The Dark Knight, but of course, the title turned out to wonderfully capture the second Batman movie's grim themes. The pointed reference to "darkness" in the Star Trek sequel's title may indicate that this will be an equally grim follow-up to the breezier first film.

4. It's a reference to Joseph Conrad's Heart of Darkness
"Will the movie be a Star Trek take on Joseph Conrad's Heart of Darkness?" asks Nathan Birch at Uproxx. It's not as crazy as it might sound. The 1902 novella tells the story of "a crew sailing a boat into unsettling new territory in search of a man who's gone dangerously mad with power and set himself up as a God." If you update the setting from Africa to space, and change the main character to Captain Kirk, it "pretty much sounds like a Star Trek plot already."