SPOILER WARNING: This article contains major spoilers for "Welcome to Hong Kong," the latest episode of Arrow Season 8.
Lyla Michaels, aka Harbinger, is living up to her codename. "Welcome to Hong Kong," the latest episode of Arrow Season 8, suggested she has worked with the Monitor longer than anyone else knows. As the episode drew to a close, Lyla met with the Monitor in secret -- and when they spoke, she did so with an air of familiarity.
"You should have told me what was going to happen on Earth-2," she told him, furious, as he stepped out of the shadows. "John was there. He could have been killed." This sentiment indicates he knows her well enough that she didn't need to clarify that Diggle is her husband.
"The destruction of that Earth was a necessary sacrifice," the Monitor replied.
"And what about Laurel Lance?" Lyla asked. "Her friends? Her family?"
"And countless more like them will perish if we do not ensure that Oliver Queen is prepared for what is coming," the Monitor shot back. "Were you successful?"
"Yes. I have Dr. Wong," Lyla confirmed.
"Then let us proceed," the Monitor said, and the episode came to a close. At the time of writing, it is unclear what the Monitor's true plan is or what it has to do with Dr. Wong and the Dwarfstar particles Oliver retrieved from Earth-2.
In Marv Wolfman and George Pérez's Crisis on Infinite Earths, Harbinger was saved by the Monitor as a child and imbued with immense powers. She summoned the heroes he required to protect the cosmic tuning forks, though she was later possessed by a Shadow Demon. This allowed the Anti-Monitor to corrupt her into killing the Monitor.
On Arrow, Lyla didn't indicate how long she has been working with the Monitor, but little is known about her background. To date, the series has only ever revealed information about her time in the military, up to and including this episode, where she shared a story of survivor's guilt with Laurel. The build-up to "Crisis on Infinite Earths" will likely reveal how her partnership with the Monitor came to be. After all, she is confirmed to play the Harbinger role in the massive Arrowverse crossover.
"Lyla Michaels as Harbinger is a key component of the original Crisis on Infinite Earths that we were determined to honor in our crossover," executive producer Marc Guggenheim recently revealed. "What makes this particularly satisfying for us is that we introduced Lyla Michaels and her Harbinger codename all the way back in Arrow Season 1."
Airing Tuesdays at 9 p.m. ET/PT on The CW, Arrow's final season stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Rick Gonzalez as Wild Dog, Juliana Harkavy as Black Canary, Katie Cassidy as Black Siren, Katherine McNamara as Mia Smoak, Joseph David-Jones as Connor Hawke and Ben Lewis as William Clayton-Queen.