Given the principle of the PhoneWave, Reading Steiner and Daru and Maho's attempt at building the time machine prototype out of the remaining parts of the PhoneWave, I came up with an alternative plot for an episode between 15 and 16 that seems to perfectly fit the plot, the tone and the dynamics of the second half of 0.
---
Maho and Daru secretly work on a prototype time machine using leftover components from the original D‑Mail device. Their goal is to help Suzuha and continue Kurisu’s research, with Amadeus assisting them. When they power the prototype for the first time, the unstable mix of old D‑Mail circuitry and new temporal hardware creates a micro‑singularity. It lasts only a moment, but it distorts the divergence field and triggers an unintended worldline shift.
Okabe collapses as Reading Steiner activates violently.
He wakes in a beta worldline where the atmosphere is tense. The lab members behave strangely: Daru is shaken, Maho avoids him, Suzuha watches him with suspicion. They all reference a plan Okabe supposedly explained the day before, a crucial discovery he made that would prevent an approaching crisis. But Okabe has no memory of it.
He realizes the truth:
the local Okabe in this worldline learned something vital, but the shift overwrote him before he could act.
The knowledge is gone forever, and the worldline is now on a path toward disaster.
When Okabe admits he doesn’t remember anything, the lab members think he’s lying or giving up again. Daru accuses him of abandoning them. Maho is hurt and confused. Suzuha is furious. One by one, they turn away from him.
Only Mayuri stays.
She sees his distress and quietly asks if he’s hurting again. Okabe breaks down and tells her he cannot save this worldline, not because he refuses to try, but because the information needed to save it no longer exists.
Mayuri takes his hand and tells him she believes him.
Together, they run to the lab at night. While everyone else thinks Okabe is fleeing responsibility, Mayuri helps him set up the D‑Mail machine. She hands him tools, steadies his shaking hands, and stays close even though she doesn’t understand the science.
Okabe apologizes for failing. Mayuri tells him there is nothing to forgive.
The machine activates. As the divergence shifts, Mayuri holds onto his sleeve until the last moment. She tells him she’ll be waiting for the Okarin who comes back.
The D‑Mail fires.
Okabe disappears into a new worldline.
Mayuri remains alone in the doomed timeline - not angry, not betrayed, simply trusting that somewhere, he is still fighting.
---
I tried to make this alternative episode fit the narrative as closely as possible, but if you notice any plot holes or inconsistencies, feel free to discuss them.
The idea came from thinking about how Reading Steiner overwrites the ‘local’ Okabe’s memories, like in Episode 8 of 0, where he doesn’t remember dismantling the PhoneWave because that was something the overwritten Okabe did. That made me wonder what would happen if he landed in a worldline where the overwritten Okabe had crucial knowledge… and the global Okabe didn’t, leading to mistrust and a disastrous future.
My favorite part is that the malfunction causing this divergence also foreshadows the Time Leap glitch in Episode 20.