Welcome to the latest installment of Crisis Crash Course, your weekly guide to everything you need to know from the past week’s Arrowverse shows (ArrowThe FlashSupergirl, and Batwoman) to prepare you for the upcoming Crisis on Infinite Earths crossover! Last week saw a pair of Crisis-heavy episodes of The Flash and Arrow, featuring anti-matter walls, dwarf star particles, and even the destruction of Earth-2. This week’s Arrowverse shows were a bit more grounded, while still adding a few new elements—and at least one key character—to the ongoing countdown.


The first newly-added Crisis element is literally a chemical element. In this week’s episode of The Flash, a new version of Harrison Wells (Tom Cavanagh) popped up on Earth-1. “Nash” Wells told Cisco (Carlos Valdes) and Iris (Candace Patton) that he’s looking for something called eternium, which he described to them as a “multiversal element.” What’s more, his wrist-worn eternium detector, which goes ding when there’s stuff, went ding a whole bunch when it was pointed at Iris. Whatever this eternium is, she’s got it all over her. At the end of the episode, Nash returns to the alley where he encountered Cisco and Iris, apparently having found a bunch of eternium down in the sewer.


So what is eternium? We don’t really know at this point. Both Iris and Cisco have traveled to alternate Earths before, so it’s likely not related to multiverse travel. If I were to hazard a guess, I’d say it has something to do with being in proximity to The Monitor, something Iris has been and Cisco has not.

An element called eternium has appeared within DC Comics pages before. In Legion of Super-Heroes #110, a group of scientists destroys The Rock of Eternity, home to the wizard Shazam, sending fragments of the shattered rock out into space and stranding future Captain Marvel Cece Beck, aka Thunder, in the 30th Century. The fragments of the rock came to be known as eternium, and acted similarly to kryptonite for Superman, draining Thunder of her strength when she came within its proximity.

From LEGION OF SUPER-HEROES (1989) #111.

You may be thinking, ‘What does this have to do with Crisis?’ Well, it really has nothing to do with Crisis on Infinite Earths, unless you count the fact that, pre-Crisis, Captain Marvel and the rest of the Marvel Family existed on the alternate Earth-S. There’s another Crisis, though, where it does come more into play. In 2005’s Infinite Crisis, a follow-up to the original Crisis, The Spectre kills the wizard Shazam, which leads to the destruction of the Rock of Eternity in the skies over Gotham.


The Rock of Eternity’s destruction in turn releases the Seven Deadly Sins on the world, and indirectly leads to Jaime Reyes finding the scarab of the Blue Beetle. Before Infinite Crisis would end, though, the rock would be rebuilt by a group of magical DC heroes, and the Seven Deadly Sins returned to their prison.

Again, not sure what this might have to do with the Arrowverse Crisis at this point (unless it means Zachary Levi might pop in as Captain Marvel Shazam!, which would be quite the coup), but good to know there is precedent for an element called eternium in the DCU, and for its creation to have ties to a past Crisis.

Dr. Jonathan Wong

This week’s episode of Arrow found Oliver (Stephen Amell) back on Earth-1 and on another assignment from The Monitor. After last week’s retrieval of dwarf star particles from Earth-2, Oliver was tasked with finding Dr. Jonathan Wong (Derek Lowe) and bringing him to The Monitor, who gave no reason for needing the doctor. Oliver and Diggle (David Ramsey) would learn that Wong is a biophysicist, and that he’d been working on a chemical weapons project for the Hong Kong government.


This one is a complete mystery to me. To my knowledge, and as far as I can find anywhere online, there’ve been no notable characters named Jonathan Wong in the DC Universe, much less associated with any Crisis-related events.

Permit me to make a leap, though, if you will.

There is a notable DC Universe character who hails from Hong Kong, is a physicist, has a connection to dwarf star particles, and who we know will be appearing in the coming Crisis on Infinite Earths.


Ryan Choi took up the mantle of The Atom in 2006 following the disappearance of his mentor, Ray Palmer. Deadline reported last month that Supernatural actor Osiric Chau will be appearing as Choi during the crossover. Choi’s existence in the Arrowverse was first teased last year, when the time-traveling Nora Allen (Jessica Parker Kennedy) presented her father, Barry Allen (Grant Gustin), with a new Flash uniform, mentioning that Ryan Choi designed it. We also know that Ray Palmer (Brandon Routh) will be leaving Legends of Tomorrow as a series regular following the Crisis.

In the Arrowverse, could Choi have been a protege of Dr. Wong, who goes searching for his missing mentor and instead stumbles upon The Monitor and the events of the Crisis? One notable aspect of the Marv Wolfman & George Pérez‘s Crisis on Infinite Earths series was The Monitor’s creation of multiple new heroes, be they new iterations of existing heroes or altogether new characters. Perhaps The Monitor had Oliver retrieve those dwarf star particles so he could give them to Ryan Choi when the time is right?

Lyla Michaels/Harbinger

Audrey Marie Anderson first appeared on Arrow in the recurring role of ARGUS agent Lyla Michaels back towards the end of the show’s first season. Over the course of her time in the Arrowverse, Lyla has advanced through the ranks of ARGUS to become its director; she’s reignited a relationship with ex-husband John Diggle, ultimately remarrying him and mothering his son; and she has teamed with both Team Arrow and Team Flash on multiple occasions as a representative of ARGUS.

We learned this week that she has also, unbeknownst to anyone, been secretly working for The Monitor. For a long time.

Audrey Marie Anderson as Harbinger

The full extent of the relationship between Lyla and The Monitor is at this point unclear, as the connection between the two was just revealed at the end of the most recent episode of Arrow. At one point in the episode, Lyla told a story to Laurel (Katie Cassidy) about how she lost her whole platoon to an IED in Afghanistan while she was on desk duty one day. She said that she tried to make a deal with any supreme being that would listen to change things, and when Laurel asks her if it worked, Lyla replied quietly with “sort of.” Later, following the rescue of Dr. Wong from the Triad, Lyla took Wong to an ARGUS holding facility before meeting with The Monitor to tell him she had Wong. She also questioned why The Monitor didn’t tell her what was going to happen on Earth-2.

It sounds like, in the Arrowverse, Lyla made some sort of deal with The Monitor back when she was in the military. It was in Afghanistan that Lyla first met John Diggle—could the deal she made with The Monitor have been to spare Diggle’s life? The Monitor made a similar deal with Oliver during last year’s “Elseworlds” crossover to spare the lives of Supergirl (Melissa Benoist) and The Flash (Grant Gustin), which is how he ended up as The Monitor’s errand boy this year.


Lyla first appeared in The New Teen Titans Annual #2 as The Monitor’s most trusted assistant, but her origin was not revealed, and she was not transformed into Harbinger, until the beginning of Crisis on Infinite Earths. As a young girl, Lyla was the survivor of an accident that killed the rest of her family; she was rescued and raised by The Monitor aboard his satellite. When the Crisis arrived, The Monitor imbued Lyla with the power to become Harbinger, which allowed her to create doppelgängers of herself. She sent those doubles out across the multiverse, recruiting heroes to The Monitor’s cause—and unwittingly exposing herself to the influence of The Anti-Monitor, who was able to take control of her and murder The Monitor.


The death of The Monitor released enough energy to save Earths 1 and 2, and Lyla relinquished her abilities in anguish following the murder, which in turn saved Earths 5, S, and X. Once the five remaining Earths were merged, Lyla became Harbinger once again, and post-Crisis would take it upon herself to document the history of the new single universe.

Will events play out similarly in the Arrowverse for Lyla once she assumes the mantle of Harbinger? Hopefully in the coming weeks we’ll learn more about how long she’s been working for The Monitor, and what the full nature of their deal is.

That’s it for this installment of Crisis Crash Course! Coming up next week: what will Oliver learn about The Monitor in Nanda Parbat? Will Nash Wells tell us what eternium is? And will Supergirl and Batwoman ever join in the fun? Be sure to check back next week, and every week until Crisis begins on The CW on Sunday, December 8th.