Three months before the field trip, Julian’s high school sweetheart, Eleanor, moved back to Pennsylvania with her four-year-old daughter, Sienna.

Julian told me Eleanor was struggling after a difficult separation and needed help getting back on her feet, and I believed him, because I was still the kind of woman who believed him, and because helping a person in trouble is a good thing, and I did not yet see the shape that was forming.

He found Eleanor an apartment.

He introduced her to his business contacts.

He arranged for little Sienna to be enrolled at Leo’s private school.

And then, slowly, the center of our family’s gravity began to shift.