Severance Season 2: How Mark & Devon's Light Message To His Innie Works

Warning! This article contains spoilers for Severance season 2, episode 3.

In Severance season 2, episode 3, Mark and Devon try to get a message to Mark's Innie using light, begging the question of how it works. After Severance season 1's climactic ending, the first two installments of season 2 focused on the fallout. From the perspective of both Severance's Innies and Outies, the aftermath of activating the Overtime Contingency was outlined, including Mark and Devon's suspicions of what Mark's Innie meant after shouting "She's alive!" in the final scene of season 1.

As the audience knows, Mark's Innie was talking about Ms. Casey/Gemma, Outie Mark's wife whom he believed to be dead. The characters of Severance present for Innie Mark's outburst have since spent season 2 figuring out exactly who he meant, be it Devon's baby Eleanor or Gemma herself. As the Innies similarly try to figure out where Ms. Casey is in Severance season 2, Outie Mark and Devon try to get a message to clarify who the subject of severed Mark's warning was, begging the question of how their light-based plan was intended to work.

Mark Is Trying To Burn A Message Onto His Innie's Retinas That Will Last For The 2 Minutes It Takes To Get To The Elevator

Mark's Plan Is Admirable But Flawed

Mark's light message in Severance season 2, episode 3 (2025)

At the beginning of Severance season 2, episode 3, Mark is shown entering his work at the Lumon office. However, things are noticeably different, from his stopwatch timer to the way he rushes to get down the elevator as quickly as possible. Later, it is revealed that Mark is timing how fast he can get from his car to the severed floor so that he can transmit a message to Innie Mark via the burning of his retinas.

Mark intends to use a light behind a message to burn his retinas so that the words "Who is alive?" will be visible to Innie Mark on any blank space. This is a common effect of looking at bright lights or simply staring at something for a long time, which results in the subject - either an object, symbol, or words - being reflected on a blank space, even closed eyelids. Mark hopes to get the message to his Innie as a way of confirming who the latter meant by "She's alive."

Why Mark & Devon's Plan Doesn't Work

The Light Plan Was Almost Guaranteed To Fail

As most will already have concluded upon the reveal of Mark and Devon's plan, it was most likely never going to work. For one, on a simply biological level, Mark's retinas being able to hold the burned image for the two minutes it would take for him to enter work is impossible. When this effect happens, the reflected image lasts for a few seconds at most. On a more sci-fi level, the show's premise provides reasons as to why Mark's plan would not work, as pointed out by an unanswered question from Severance season 1: Reghabi.

Reghabi appears in Severance season 2, episode 3 as Mark sits in his car attempting to burn his retinas. Reghabi tells him it will not work, not only for logistical reasons but because the elevator at Lumon dilates employees' pupils, rendering anything seen before entering null and void. Reghabi also insists that Mark has a higher chance of blinding himself with the light plan than successfully getting a message to his Innie, before asking how Mark's Innie would get a message back to the outside.

Why Irving Was Able To Give His Innie A Message But Mark Can't

Irving's Strange Phone Call Proves Messages Can Be Transferred

In Severance season 2, episode 2, Irving's Outie had a mysterious scene as he entered a phone booth, telling the unseen caller that his Innie got the message. This begs the question of how Irving got a message to his Innie, yet Mark could not. The most obvious theory for this links to Severance's Overtime Contingency, which saw Innie Irving awaken in Outie Irving's apartment. The former saw many paintings from the latter depicting a dark hallway with an elevator at the end, confirmed to be Lumon's so-called "Testing Floor" that is key to the investigation of Severance season 2.

Outie Irving was not sleeping outside of work, allowing Innie Irving to dream about the black paint to further the message...

While Outie Irving could not have known about the Overtime Contingency being activated, his countless paintings may have been a failsafe to ensure that - if it ever was activated - Innie Irving would notice them and investigate the Testing Floor. Moreover, Outie Irving was not sleeping outside of work, allowing Innie Irving to dream about the black paint to further the message, linking the two via their subconscious.

What this does not answer, however, is how Outie Irving knows that his Innie received the message. This likely links to the mysterious person Irving was calling, who is potentially even an ally of Reghabi. Unanswered questions aside, Severanceseason 2 has made it clear that Irving has managed to contact his Innie in a way, yet Mark failed to via the light-based plan that he concocted alongside Devon.