Fundamentally, we continue ahead until we find the stairs to the next floor, and then decide whether we'll continue or return later.
In the case that we return later, afterwards, we take a straight line back to the point where we made it last time, and advance the exploration.
Last time, we descended down to the third floor, all at once, but it isn't limited to this time.
Since it seems that the longer a trip runs the greater probability that we'll fall into a trap, I guess, we greatly desire speed.