Without the Purple Smoke, they naturally had no way to cross the sea and return to the Six Continents.
But before heading to the Dark Continent, Moyu had made an agreement with Killua and asked Ikushube to keep a contingency in reserve.
It was meant to give them a chance to return if their route home was cut off.
Thankfully—
Cell phone reception in the Hunter world was absurdly good. As long as one was within the world's mapped territory, signals could be received almost anywhere.
And cell phone development had flourished, with all manner of dazzling functions.
For this expedition to the Dark Continent, everyone on the team had been given the latest model of phone, equipped with solar charging, so they could run the translation software Piyon had specially created.
Although they never ended up needing that translation software, it had preserved countless precious photographs from the journey.
When Moyu and the others left the wasteland, they were quite surprised to discover that their phones could actually receive a signal.
Perhaps it was because they were relatively close to the Six Continents.
Or perhaps V5 had extended its reach into the Undeveloped Seas long ago and had already solved the communication issue.
After all, a large Transit Station had been built along the boundary waters.
Or perhaps the Kakin Empire had already transported batches of humans to the Imaginary Continent and, through an endless supply of labor, completed extensive infrastructure work in a short time.
In any case, as long as there was even a weak signal, Moyu could use Ikushube to contact Killua directly and have Killua use the Wish Machine's power to send them straight back to the Six Continents.
Moyu's original agreement with Killua had been that, one year later, whether or not there was