Marle Paradox: Let's change our point of view

[Mortalshuffle]

What you say about the gate key, Desrever2, is something I’ve been considering for a long time now. It’s enough to make me come out of lurkdom.
Who’s to say that the gate key isn’t the thing giving immunity to our characters?

What happens to Marle is not an anomaly. It’s a glimpse into a plot point that will be important later in the series in the form of the Darkness Beyond Time. This means time travelers in themselves don’t necessarily have immunity to the effects of the changing timestream. The gate key is an item our characters are always carrying with them that clearly has an effect on time travel. What’s the one thing that can detect and open gates? The gate key. So why shouldn’t it also be capable of other things, such as protecting the existence of the time travelers’ carrying it? It wouldn’t be the only time we’ve seen an item with time-protective capabilities: Kid’s pendant is capable of rewinding her personal timeline to an earlier point to keep her from dying.

The only time in the game that the grandfather paradox occurs is during the first time trip through time. Marle has no gate key and disappears before Lucca arrives on the scene to get within proximity to her with the gate key. It’s only after the missing queen is returned and the timeline straightened out that Marle returns – and only when Crono and Lucca get close to the spot where she disappeared. Seeing as they were carrying the gate key at the time, circumstances could lead us to conclude that the gate key was what drew her back once the timeline was restored, and without it she would have remained in the DBT due to the change of when Leene was rescued.

As for Ayla, the gate key could easily be what allows Ayla to travel with the group and place herself in danger without negating the existence of Marle.
The gate key could really explain a lot. When Magus returned to 12,000 BC, he had to stay as close to the original timeline as possible or else he would affect his own existence and be unable to save anyone. He wasn’t prepared to time travel when he was sucked into the black gate so he had no gate key equivalent of his own. He had to bide his time and wait until the opportune moment to strike – when Lavos emerged.

[Thought]

What you say about the gate key, Desrever2, is something I’ve been considering for a long time now. It’s enough to make me come out of lurkdom.
Who’s to say that the gate key isn’t the thing giving immunity to our characters?

Because Chrono doesn't use it when he travels to 600 AD but isn't affected when Marle disappears (that is, he remembers she is supposed to be there). Thus, he seems to be immune to changes in the timeline before coming in contact with the key. Orare you saying that meeting up with Lucca shortly afterwards retroactively protects him from the same time change that affected Marle?

Additionally, your stance requires that the Epoch grant the same immunity even though it and the Gate Key do not share the same tech.

However that said, I would agree that Time Travelers are not immune from changes to the Time Line, nor are particular itterations of them immune.

[Mortalshuffle]

We see in-game that characters don’t forget their original pasts. For instance, Magus seems to remember a past in Zeal where the heroes of the game weren’t on the scene as we see in his flashback on the North Cape. Why should Crono be any different? Lucca also seems to remember a past where her mother was paralyzed by that machine, or at least that’s what I inferred.

If not, the pendant could have protected Crono from forgetting. We see in Chrono Cross that Kid’s pendant is capable of rewinding time to an earlier point to keep her from dying. There may have been residual energy in Marle’s pendant from the Mammon Machine – not enough to open doors or chests with crests on them, nor enough to rewind time, but enough to protect its wearer from endangering their own timeline or forgetting certain things.

The Epoch might not protect our characters the same way the gate key could. Belthasar is so far from the past that anything he does in 2400 AD or 1000 AD won’t affect him. As a result he can use the Epoch or the Chrono Trigger willy-nilly with nary a consequence to his personal timeline. By the time Crono and company get the Epoch, they’re still carrying the gate key with them. The Epoch doesn't need to grant the same immunity.

Thinking on it, Belthasar’s original plan may have been to return back to his home time via the Epoch, get the Chrono Trigger from Gaspar, return to 2400 AD, and use it on Death Peak to rescue Schala. Belthasar’s machinations would have to be very precise to keep the timeline intact and be able to rescue Schala. Unfortunately, that version of him died before he could complete his objective. The new version had to deal with a significantly altered timeline thanks to the intervention of Crono and company, and had to reformulate his plan. Perhaps the new Belthasar did go to 12,000 BC first when he completed the neo-Epoch, but found that the Chrono Trigger wasn't completed yet and couldn't be used, and that's where the ridiculously complex plan of Chrono Cross came from.

[Thought]

See, that's the rub. Why should a change to a timeline make someone disappear but not make people forget? If Marle lacks TTI because she didn't travel with the Key, then Crono would also lack TTI because he didn't travel with the key, so if Marle disappears, Crono should forget. If Crono remembers, Marle shouldn't disappear. The problem is that Marle disappears and Crono remembers, an outcome that should be impossible as people generally understand the nature of time travel.

And you pointed out a problem yourself; Magus, Melchior, and Belthasar all traveled without a Gate Key or the Pendant yet their knowledge of 12,000 BCE is unaffected by changes to the timeline, indicating that whatever grants immunity (if immunity is granted) ain't the Gate Key or Pendant.

Regarding Belthasar, generally it seems like he wasn't aware of Schala's fate at that point.

[Mortalshuffle]

Why do memory and existence have to be tied together? Perhaps TTI exists for all time travelers, but in a way that’s different than what is usually assumed -- it exists only for their memories. Their physical existence can be erased without affecting the memories of time travelers in the era in which they disappear or an earlier era.

Actually, the Telepod could have been what protected Crono and Lucca’s memories in 1000 AD before they time traveled. Lucca did invent the Gate Key out of its components. They may have been close enough to it to remember Marle in an era where she no longer existed. Then Crono went to 600 AD where TTI took effect on his memories once he was out of range of the Telepod by about 400 years.

Crono remembers and the people indigenous to the Middle Ages clearly remember Marle, even after she ceases to exist. Perhaps the memories stay in order to keep a grandfather paradox from forming. It may be a defense mechanism for the DBT to keep the cycle of the same two possible futures from repeating ad infinitum.

TTI may have been protecting Magus’ original memories since he was in the same era in which the change occurred. If not, then his exposure to the Gate Key when the crucial change in timeline was happening may have been what protected his memories. Neither Melchior nor Belthasar talk about those specific events in their new eras post-change, so we don’t know which version they remember. I’m inclined to believe they remember the altered version.