When in Harmony Six, 16, and the winking woman finally find the Sea. They go running towards it, 16 does more, he runs into the waves, splashing about in the water. But Six is afraid, afraid because he lost his brother to the sea when he was a boy, and now he's afraid the same is going to happen to 16.
It is through Six's sudden fear that he conjures up the Guardian, and because of that 16 is lost to the sea, taken below the waves by the Guardian to drown. A terrible death? Well its worse than that, because really the sea doesn't exist! So when the Guardian appears it does so out of the sand. As for 16, he does drown but not in water, but in a sea of sand. That is a terrible way to die! And yet later when Six takes 313 to see the sea, it's gone, there is only the sea of sand, the desert! The sea was never there you see, it does not exist.
It is, as it is, as it should be.
Be seeing you