On Saturday the Swans go shopping, and Alli picks Bella a dress; it's dark viridian and sleevelessly strikes a happy medium between "it's barely been autumn for two weeks and this is Arizona" and "school dress code". For herself Alli goes with carnation pink and a slightly riskier neckline. There passes a second week of school.

And then it is their birthday.

Bella was born first, at a quarter after one in the afternoon, so they have plenty of time to go out for a celebratory lunch and for Renée to frost the cake she made the previous evening.

Bella has just taken a bite of her corner of the sheet cake when it hits.

She grins.