She went up the stair as far as she could go, eyeing the hot rubble in case a way past it had opened up. She could now discern a gap below the under-spiral of the stair, but everything radiated such heat that she could not get near it. Here and there, ribbons of molten metal, shiny as quicksilver where their coatings of grit had cracked, congealed in puddles on the treads.

It had to be the outside. Ullii squeezed through an embrasure that did not face the yard and found herself just above one of the roofs of Fiz Gorgo. She lowered herself to a roofing slab, adjusted her mask so it allowed in just a slit of light, and looked up.

The tower had been built of rough stone and the joins offered many hand-and foot-holds. Ullii was naturally dextrous, so the climb would not have been beyond her, had the tower been dry. Besides, her lattice revealed its secret strengths and flaws in a way that no one else could see. She looked up, closed her eyes and its network of cracks, crevices and stress-points opened up to her.

She pulled herself as far as the next floor, the fifth, but above that the stone was too hot to hold on to. Ullii edged sideways around the tower, one eye on the yard. If anyone looked up she would be seen, for her pale clothing and skin would stand out against the dark stone.

Fortunately the rain had become heavier, and colder, and the soldiers in the yard had their hoods down. Curling her toes around a projection no thicker than her finger, Ullii eased around the curve of the tower until she was directly above the yard. If she fell, she would die.

Above her, at the lower point of the bend, the wall was networked with horizontal cracks. If she could cross above them the worst would be over. She went up, stretched sideways to reach a convenient crack shaped like a lyrinx's smile, and up again, sliding the fingers of her left hand deep into a crevice. She jerked them out and thrust them into her mouth – the inside was hot. She turned her head from side to side, eyes closed, sensing the heat on her cheek. There, to her left and above, where the rock was cracked like a mosaic, it felt cooler. It didn't look very stable, though.