The planet of Maltus, ten thousand years ago. Mar Novu – who would become the Monitor – and his wife begin a temporal jump experiment to take Mar to the beginning of time. The experiment works, but his presence corrupts the area, releasing anti-matter. Mar is shunted to the anti-matter universe where he sees the creation of the Anti-Monitor.
At the Vanishing Point, Ryan Choi tries to come to terms with what’s happened in the months of relative time since they arrived, recording that the other Paragons are all withdrawing into themselves, with the exception of the Flash who has left. He and Lex attempt to build a transporter but it fails moments before Flash returns. For him only moments have left since he attempted to access the Speed Force without success.
Green Arrow – now the Spectre – sits in Purgatory with Jim Corrigan who has prepared him for his next, final, and greatest challenge: to fight the Anti-Monitor. The Spectre next appears at Vanishing Point, telling the heroes that the Speed Force is the key to saving everyone. He informs them that the Anti-Monitor is at the dawn of time and it is there that they need to defeat him, but also tells them about Mar Novu’s experiment on Maltus, and that they have to stop him releasing anti-matter in the first place.
The Spectre gives Flash the ability to access the Speed Force and sends Supergirl, Ryan, and Lex to Maltus. Flash meets the Spectre within the Speed Force who tells him to find the other heroes who have been scattered amongst the Force due to an attack by the Anti-Monitor.
The first person Flash finds, though, is the Flash from the Justice League film, who shouldn’t exist now that the multiverse has been destroyed. After a brief conversation, the film Flash disappears.
On Maltus, Lex attacks Supergirl and Ryan with new powers he has given himself from the Book of Destiny.
In the Speed Force, Batwoman sees a meeting between Oliver Queen and Ray Palmer from years before, and is surprised when Oliver can see her. Elsewhere Green Arrow and Supergirl talk during the Invasion crossover when they are joined by Martian Manhunter.
On Maltus, Supergirl and Ryan recover and head to Mar Novu’s experiment.
In the Speed Force, Flash sees the final battle between Dr Destiny and Superman with the arrival of Green Arrow. Flash and Green Arrow talk, Arrow remembering everything. He tells Flash that Arrow made a deal with the Monitor to give up his life to save Flash and Supergirl.
Also in the Speed Force, John Diggle and Laurel Lance stand over the corpse of Black Canary before they are joined by the Flash.
On Maltus, Lex interrupts Mar Novu and tells him of the result of his experiment, offering to help him in return for abilities to tackle Supergirl and the other heroes.
In the Speed Force, Flash revives Black Canary and takes her from Diggle and Laurel. Martian Manhunter tells Supergirl and Arrow that they are friends before Flash takes him. Batwoman recognises that Arrow never trusts people at first and that is something that she needs to work on herself, before Flash takes her as well.
Supergirl interrupts Lex and Mar Novu while Ryan Choi takes Mar and attempts to convince him not to conduct the experiment, Supergirl and Lex battle. As Ryan ends the fight by telling them Mar is no longer going to undertake his experiment, Flash arrives and takes them all to the beginning of time in the anti-matter universe.
There they face the Anti-Monitor who explains that even though Ryan convinced Mar Novu not to perform his experiment, somewhere in the multiverse at least one Mar Novu would do it, thus ensuring the Anti-Monitor’s creation.
The Spectre appears and tells the heroes that they need to hold the line against the Anti-Monitor and his shadow demons in order to buy time to restart the universe which can only be done at the dawn of time.
The Anti-Monitor and Spectre fight each other as the other heroes fight the shadow demons. With the demons defeated, they turn to Lex – as the replacement Paragon of Truth – to work out what they need to do. With his prompting, each of the Paragons focus on their own particular strength, feeding their will to the Spectre. Spectre and the Anti-Monitor explode, rebooting the universe, resulting in the second death of Oliver Queen, who passes after encouraging Flash and White Canary to keep going.