She was about to abandon her hiding place when she heard the chorister at the gate. He rattled the latch, satisfied himself it was fastened, and went on.

He’s going into the vestibule, she thought, and then he’ll go check the door, but instead she heard the rattle of another gate, and then a clank, and footsteps ascending a staircase. The Wren Geometrical Staircase.

But it’s boarded up, she thought, and then remembered Mr. Humphreys saying they were debating whether to open it again, in spite of its fragility. Because the staircase led to the roofs.

I must have gone straight past it in the darkness when I ran into the church, she thought, cursing herself. If she’d remembered it, she could have found John Bartholomew by now.

The chorister climbed up a few more steps and then walked back down. She heard him latch the gate, and head up the aisle toward the dome.

It took every ounce of self-control she had not to plunge out of the chapel and over to the staircase. She waited till the chorister’s footsteps had died away, counted to ten, squeezed out of her hiding place, and tiptoed over to the gate. The south aisle and the nave beyond were full of smoke. It stung her eyes and made her want to cough. She forced the cough back, holding her breath, and looked up the nave toward the dome—and saw flames.

Oh, God, the roofs caught fire after all, she thought, and then saw that the flames were from scraps of burning paper and pieces of wood swirling in the air below the dome.

They must be blowing in through the shattered stained-glass windows from the fires in Paternoster Row. The air was full of them. A burning order of worship danced down the nave and sank to the stone floor, still alight and dangerously close to the Christmas tree which stood next to the desk where she’d bought her guidebook. And even here, in the south aisle, the air was full of ash and glowing sparks. One landed on Polly’s coat, and she batted at it as she ran toward the spiral staircase. She opened the gate and started up the curving steps.

And heard flames crackling. The tree, she thought, and darted back down the steps and out into the nave, but it wasn’t the Christmas tree. It was the visitors’ desk. Flame and smoke curled up from the counter.

Perhaps it’s only the guidebooks, she thought. But as she watched, the wooden rack caught fire, the postcards Mr. Humphreys had shown her of the Wellington Monument and the Whispering Gallery going up like struck matches.

Where’s the fire watch? she thought. This is their job. I have to find John Bartholomew.

But by the time they found it, the fire might have spread. Scraps from the burning postcards were floating, still aflame, up the nave toward the wooden chairs, the wooden pulpit.

And what if this was a discrepancy, the result of Mike’s having saved Hardy or of her having influenced Marjorie to go meet her airman? What if, thanks to us, St. Paul’s did burn down? she thought.