In The Time of Dinosaurs

<Once a Sario Rip - a time-rift - is created, there is no difference between a year and a million years. The energy required is the same. I think I remember the equations ... in an equation where t is time, z is Zero-space, w inversely cubed represents the nexus of ->

[...]

We would attack the Nesk home base and seize an explosive weapon. A bomb. A "nuke," as my human friends said. Then we would return to the ocean and attempt to explode this "nuke" in such a way that it would close the Sario Rip and return us to our own time.
I hoped the Mercora would have some idea how to do this. I certainly didn't. We learned about Sario Rips in school. But I wasn't really paying attention that day, and I can't be expected to remember all the things I learned in school. Can I?

[...]

"So okay, now we have to figure out where and when to use this nuke," Jake said.
<The Mercora have agreed to let us use their computers,> Ax said. <With their help, I can probably recreate the theory behind Sario Rips, and then come up with an accurate plan.>