In the future, Kiera contemplates suicide when she falls victim to a terrible chemical weapon attack. Thankfully, a cure arrives just in time.
In the present, Kiera meets with Alec at his lab to see if he has any updates on who killed Other Kiera. His supercomputer is nearly overwhelmed trying to process the data from dead Other Kiera's CMR suit. He promises that as soon as it does, it'll get sent directly to her CMR for review. Alec can sense that Kiera is still wary about him; he pledges to disappear into this timeline with Emily, never to be seen or heard from again.
At the Freelancers compound, Kiera meets with Catherine. The leader demands that it's time for Kiera to choose which Alec should remain in the timeline. She begs for more time but Catherine refuses to budge: the choice must be made in order to prevent future degradation of the continuum.
As Alec and Emily plan their escape, they realize that Other Alec has all but squashed their ability to flee by freezing all of Alec's accounts and access. Alec suggests turning to Kellog for financial and other less-than-legal help. Emily only agrees to accept Kellog's help if Alec can find a way to destroy Escher's damning file on her true identity.
Meanwhile, Liber8 breaks in and steals something from a Sonmanto chemical plant and make no effort to hide their break-in. When Kiera and Carlos respond the next morning to investigate the scene, they are surprised to encounter Mr. Richardson, Sonmanto's evasive, placating lawyer. It's obvious some kind of cover up has already begun.
When Emily confronts Other Alec about letting her and Alec go, he refuses to budge, insisting he wants to keep the both of them on a short leash. Emily snaps and body slams Alec and his bodyguard in front of the PIRON building. She demands that Other Alec let them go or next time, she won't hesitate to permanently eliminate him. As she leaves a stunned Other Alec on the sidewalk, she tucks away an PIRON access card she managed to pickpocket from him during their scuffle.
At Sonmanto, Kiera analyzes the chemicals that Liber8 stole. Her CMR doesn't tell her much, so she seeks out Other Alec for help. At first, he won't answer her calls over her CMR or via cell. After a text message indicating Liber8's involvement, he finally responds, agreeing to help. He reveals that with just a few additions of commonly found chemical compounds, they realize that Liber8 has created the mother of all chemical weapons - and they're out to poison the city. Kiera puts both Alecs to work, as Other Alec gets to work on creating an antidote while she calls Alec to track down Liber8's location. He makes quick work of it and finds from where they stole their truck for their burglary.
Back at the precinct, Carlos accuses Betty of taking her time tracking down Liber8 so they have time to escape. She defensively reveals that she's spent so much time and a lot more effort pinpointing Liber8's exact location. Carlos storms off in a huff while Kiera warns Betty to check her attitude.
As the SWAT team closes in on Liber8 at a warehouse, a firefight ensues and one member sacrifices himself, unleashing the deadly toxin into the air. Carlos and the other SWAT team members make it out safely. Kiera finally stumbles out, choking, and collapses. Thankfully, she survives because of her immunity from the toxin in the future.
Alec disguises himself as Other Alec, down to suit, tie and styled coif. Using the access card that Emily pinched from Other Alec, he gains entry into PIRON's headquarters and gets to work trying to destroy Escher's file on Emily.
Kiera and Carlos head to Sonmanto headquarters. With Other Alec's analysis of the toxin, she determines that Liber8 has accelerated the same chemical weapon from their future. When Other Alec tries to log in remotely to his computer at PIRON, he's denied access and realizes that something is up. As Alec struggles to gain access to the file on Emily, Other Alec returns. In a desperate act, Alec knocks out Other Alec with a keyboard.
At Sonmanto's headquarters, Gord Solomon (Liber8's "lawyer") announces to a throng of press that not only did Sonmanto know about the ability to weaponize their chemicals, they've already begun profiting from that knowledge. In a rage, Kiera detains Solomon in front of the media crowd. Tearfully, she confesses to Carlos her betrayed realization: Sonmanto didn't just make the antidote in the future - they also manufactured the toxin that killed people she knew and nearly killed her. When Kiera pings Other Alec for additional information on Sonmanto, unbeknownst to her, she gets Alec instead on her CMR. Alec sends her the ruinous files on Sonmanto just as Other Alec rises from his stupor. Other Alec now has a very prominent wound on his forehead in the same spot where Alec has his scar. The pair begin arguing and Kiera can't tell who's who on her CMR. She heads to PIRON.
Carlos confronts Mr. Richardson as he tries to assure that gathered media that Sonmanto had no clue about it's own potential chemical weapons. Not only does Carlos provide proof of illegal arms dealing, he even gives the media a disastrous sound bite: "For once, Liber8 did a little good" as he places Mr. Richardson in handcuffs. For this, Dillon puts Carlos on desk duty until the media storm blows over.
Back at PIRON, Alec comes to the painful realization that Other Alec is still in love with Emily but won't let her go. With no options left, he forces Other Alec to destroy her file at gunpoint. Just as Alec is about to kill Other Alec, Kiera appears, having snuck in with her invisibility suit. As each Alec pleads their case in a tense standoff, Kiera shoots Alec, sending him to the ground. Other Alec is stunned. Luckily, Alec isn't dead, but instead he's turned over to the Freelancers who place him in their remote time-locked prison. Emily anxiously waits to flee with her lover who will never come. When she can wait no more, she flees without Alec, her violent past no longer able to haunt her.
Meanwhile, Sonya reveals their plan all along: Sonmanto will never be seen as the victor in any timeline. Using Travis' immunity to the chemical, Sonya intends to develop the antidote 50 years ahead of schedule - and Liber8 will dole it out for free when the time comes. Is this another betrayal for Carlos? His mounting frustration grows.
Kiera meets with Catherine and the Freelancers, demanding to know what will happen to Alec. When Catherine tries to enlist Kiera's help in securing the duplicate time travel device in this timeline, Kiera is interrupted by the supercomputer sending her the raw video data from the day she was shot and killed: her killer is Curtis Chen. She quickly subdues him to Catherine's outrage and horror, but when Kiera shows her the CMR footage, Catherine's tone becomes merciless. Looking down the barrel of Kiera's service weapon, his life hangs in the balance.