You can almost see, under the cover of decades of vines, the tower, its brickwork inset with tiles decorated with a pattern of vines. The tower, whose stair treads sag with a creak under every footstep. The tower built precisely on the migration route so that, from the top, on certain late summer evenings as determined by consultation of multiple star charts, you can, if you lie flat on your back on the boards that are both musty and splintery (remember to bring a blanket to lie on, preferably a thick one) you can see the dragons flying overhead.

It's always a moonless night when they pass by, so you see them mainly as vast silhouettes. You feel the muggy heat of the breeze that's their wake, and see the occasional underbelly-embedded jewel streak by like a shooting star as it catches the light of a distant town.

After you watch a while, the dragons may seem to be almost close enough to touch, as if they're skimming along under a sky as low as the ceiling back in your home.

No matter how tempted you are, do not stretch out your hand. Do not try to touch the dragons. The rushing friction of the gem-crusted underbelly will burn. The sky will tremble as if with heat lightning. The claws, when they catch you, will nearly crush the breath from you.

Worst, when you return, dropped back a year later, on the same roof (you'd better hope it's been an easy winter and spring while you're gone, or the tower might have crumbled to rubble), you won't be able to find words to describe the wonders and terrors you've seen: the fiery fields that blaze on the moon's dark half, the vast and silent cold of the migration ways, the draconian cave-citadels that drift among the furthest comets. No one will believe your stories, and no one will heed your warnings -- if you do find words for them, they will do more to intrigue than to dissuade, and future summers will bring new crops of freshly-returned travelers. At least they'll believe you then.