Before she could remove anything, she was so startled by footsteps from behind her that she yanked her hand from the bag and stood upright. But it was nothing more than four men and a woman, just off the number 1 boat that stopped at Rialto at three fourteen, now crossing the campo on their way to some other part of the city. None of them paid any attention to the woman. Their footsteps died away as they walked up, then down the bridge that led into Calle della Mandola.

Again, she bent and reached into the bag and this time her hand came out with a large rock, one that had stood for years on the desk in her study. She’d brought it back from a vacation on a beach in Maine more than ten years before. The size of a grapefruit, it fitted perfectly into her gloved palm. She looked down at it, raised her hand, even tossed the stone up and down a few times, as if it were a tennis ball and her turn to serve. She looked from the rock to the window and again to the rock.

She stepped back from the window until she was about two metres from it and turned until she stood sideways, but still looking at the window. She pulled her right hand back level with her head and raised her left arm as counterweight, just as her son had taught her to do one summer when he had tried to teach her to throw like a boy, not a girl. For an instant it occurred to her that her life, at least part of it, would perhaps be divided in half by her next action, but she dismissed the idea as melodramatic self-importance.

In one sweeping motion she brought her hand forward with all her strength. At the full extension of her arm she released the rock, then staggered forward a half-step, powerless to resist the momentum of her own motion. Because the step pulled her head down, the fragments of glass that exploded from the shattering window landed in her hair and did her no injury.