If you've managed to catch Solo: A Star Wars Story in theaters, you already know what it is...
SPOILER ALERT!
...your favorite double-sided lightsaber–wielding Sith Lord is back from the dead. Darth Maul makes a 19-years-later surprise appearance at the end of the Ron Howard–directed Han Solo origin story. How? Didn’t he die in the very first prequel, 1999's Episode I: The Phantom Menace? What does this mean for future installments? All of this, young Padawan, will be revealed in time (and below, thoroughly, with relatively succinct vigor).
Maul, reprised by actor Ray Park, shows up via hologram late in the film, much chattier than his near-silent Episode I self. Voice duties went to Star Wars: The Clone Wars animated series’ performer Sam Witwer, and not Phantom Menace's Peter Serafinowicz. The change may be due to fan affinity for the animated series being arguably stronger than that of George Lucas' prequels.
Maul trained under Darth Sidious/Emperor Palpatine and famously murdered Obi-Wan Kenobi’s master, Qui-Gon Jinn, before being cut in half by Ewan McGregor's Obi-Wan. Maul fell down an archetypal Star Wars shaft, never to be seen again—until the two animated series, Star Wars: Rebels and Star Wars: The Clone Wars brought him back.
Across the two animated shows, we see Maul survive through sheer hatred, receive robotic legs from his mother, vow to hunt down Obi-Wan, and become a crime lord. (At least one of those is incorporated in the Solo reveal, but we'll let you find out.) Clearly, his survival is now canon in Disney’s modified cinematic lore, and not merely relegated to its animated counterparts.
In case you’re more of a visual learner aand desperately want a more detailed analysis of Maul’s involvement in the story, please, educate yourself with the following video.
Whenever a franchise with millions of followers decides to take a hard left turn regarding narrative or canon alteration, a wide swath of fans are going to be up in arms. (We saw more than enough of that fussiness in December with Star Wars: Episode VIII – The Last Jedi.) For a small taste of the kinds of commentary we're referring to, please, enjoy some vibrant Twitter reactions.