Rose mentioned that in the Furthest Ring, the way time and space shifts makes it so even if you take the "same" path it can take you a different amount of time (or...space) to get there. And they know for sure that the path they're on will get them there.
Dirk just kind of flew off into the distance without even caring, but if he gets anywhere at all in any reasonable space of time I'm going to assume it's because of Roxy's Void powers at work.
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