The following contains MAJOR SPOILERS for Solo: A Star Wars Story. Trust me, if you haven't seen it yet, you don't want to know. No seriously, SPOILERS. Did I mention SPOILERS?
A movie that followed the exploits of Han Solo before we meet him in Star Wars: A New Hope was bound to include appearances by characters or references to others that we know from previous films. Of course, Chewbacca and Lando Calrissian were there, but they were far from the only fan-favorite characters to appear. At the end of the film, we discover that the Crimson Dawn gang is actually answering to a character who we've met once before on the big screen. This is your last chance to avoid SPOILERS. Screenwriters Jon and Lawrence Kasdan spoke to CinemaBlend about why this character, once thought dead, was who they wanted to be the man in charge. If you're still reading this, then hopefully you already know who I'm talking about, Darth Maul. Yes, Darth Maul. Jon Kasdan explains...
If you didn't watch the Star Wars: The Clone Wars or Star Wars Rebels animated series, then you may not even be aware that Darth Maul, the Lord of the Sith apparently killed by Obi-Wan Kenobi in Star Wars: The Phantom Menace, is actually alive. He's the one apparently pulling the strings of the criminal organization Crimson Dawn.
Darth Maul was one of the more popular aspects of The Phantom Menace, which made the fact that he didn't survive the film very upsetting for many. However, that fan support was so great that the character was eventually brought back into the story when it was revealed in the Clone Wars animated series that he actually survived his battle with Obi-Wan Kenobi. In that series, Maul is motivated by revenge toward the Emperor for discarding him so easily, and he builds up a criminal empire known as The Shadow Collective.
It appears that the Collective may alive and well during Solo, as Darth Maul is clearly involved in at least one major organization, though we know little else beyond that based on the brief interaction we see between Qi'ra after she has taken control of Crimson Dawn, and Darth Maul via hologram. That scene, as it turns out, is one of the favorites of Solo co-writer Lawrence Kasdan.
Solo: A Star Wars Story leaves several open plot threads that could certainly be explored in future films. Exactly what Darth Maul is plotting is certainly one of them. We'll have to wait and see if we get sequels to this particular movie, perhaps Darth Maul will hire Boba Fett in the just-announced film being directed by James Mangold.