The latest episode of Arrow season 8 served to shoot down a popular theory regarding Earth-2 Laurel Lance and the Anti-Monitor. With the highly anticipated Crisis on Infinite Earths looming, season 8 - which also doubles as the show's last - has seen Oliver Queen working for The Monitor. Tasked with very specific missions, Oliver's journey has taken him to parallel Earths and various familiar locations from his past. Along the way, he has since been joined by John Diggle and, following the destruction of Earth-2, the former Black Siren. Recently, however, Oliver had begun to question The Monitor's agenda - wondering whether he was truly intending to help avert the coming Crisis or cause it.
Fans began to question things, too, when it was revealed that Lyla Michaels and The Monitor were secretly working together. Those questions were only exacerbated when The Monitor approached Laurel with a tantalizing offer. He revealed that he actually had the ability to restore Earth-2 and that he would do so - but only on one condition. In order to see her home and everyone she knew returned to her, Laurel would have to betray Oliver Queen. The majority of Arrow episode 5, "Prochnost", saw Laurel wrestle with that choice. Ultimately, however, she opted to turn down the offer, stating that getting her world and everyone back wouldn't be worth it if it meant reverting to her villainous ways. As such, Arrow finally made Black Siren a hero.
It had the opposite effect as far as The Monitor was concerned, however, with it theorized that he was actually the Anti-Monitor in disguise. As it happens, though, Arrow season 8, episode 6, "Reset", served to outright disprove that theory. Following immediately on from being knocked unconscious, Oliver and Laurel found themselves trapped in a time-loop. At first, they both believed it to be a punishment for Laurel turning The Monitor down and Oliver actively working against him. Especially when they were forced to watch a newly returned Quentin Lance die over and over again. In truth, however, it was actually, in part, a reward for Laurel. Choosing not to betray Oliver had been the desired outcome the whole time - confirming The Monitor was indeed the real deal. And thus giving Laurel her fondest wish: a chance to tell Quentin how she truly feels and say goodbye properly.
In retrospect, it makes a lot of sense for The Monitor to test Laurel the way that he did. Given that Oliver was never meant to interact with Earth-2, Laurel venturing to Earth-1 and joining forces with him was clearly an unforeseen complication. As a new wrinkle in whatever grand plan The Monitor has Oliver gathering pieces towards, the celestial being would no doubt deem it necessary to test Laurel's loyalty. Much in the same way that he tested various heroes during the Elseworlds crossover and multiple times since. It remains to be seen just how much and how impactful a role Laurel will play in the Crisis on Infinite Earths event. Whatever the case, The Monitor is evidently satisfied to have her on the team.
Some fans, however, will no doubt be disappointed by the lack of such a twist. After all, Crisis is one of the most beloved storylines within DC Comics history and the Anti-Monitor one of the source material's most memorable villains. As such, many are eager to see things get really kicked up a notch and an early introduction to the Anti-Monitor would certainly have done that. With only one Arrow episode (and a handful of Arrowverse episodes in total) remaining before the Crisis truly begins, fans won't have to wait much longer to see the collective universe's most dangerous and all-encompassing evil finally make his debut.