Spoilers ahead for tonight's episode of Arrow, titled "Missing."
"Missing," the penultimate episode of Arrow's fifth season, featured a number of notable returns: Yao Fei was back for a bit, and we got two different versions of Katie Cassidy's Laurel Lance, one of whom brought Artemis along with her.
There was Malcolm Merlyn, too, heading up the League of Assassins reunion committee with both Talia and Nyssa al Ghul in attendance.
The biggest return, though, was saved for the episode's closing moments, when Manu Bennett returned as Slade Wilson/Deathstroke a week earlier than fans expected (even if it was only for a moment).
Deathstroke was the season 2 big bad and has remained many fans' favorite villain in the show's history. He briefly appeared in season 3, but was fairly quickly dispatched and Bennett himself complained about the character being dispatched too easily for believability.
The last time fans saw Deathstroke was as a computer simulation in the "Invasion!" crossover, in an episode that celebrated the first hundred episodes of Arrow. It's no coincidence that tonight's episode felt somewhat similar; as the series lurches toward the season 5 finale, the flashbacks that have been a part of the series' DNA up to this point will be finished, having caught up to real time, and showrunners have indicated that the plan is to use the narrative device more sparingly, and to explore other people's pasts besides Oliver's.
The net result is that while Arrow tends to throw all of its cards in the air at the end of every season, the end of season 5 feels the most significant, and the most like a true reboot in some ways.
Series star Stephen Amell and executive producers for the series had separately told fans to expect Bennett's villain to return in the finale, with EP Marc Guggenheim sharing a set photo that included a man in Bennett's Deathstroke costume. Bennett emphatically denied that he was appearing in Arrow season 5, even after set spies too photos of him arriving in Vancouver for production.
Next week's finale will feature all of these guest stars, plus at least one additional familiar face: Nick Tarabay, who played Captain Boomerang in the first Arrow/The Flash crossover.