And yet Abigail was his favorite, I think. She was, we all knew she was, even if we’ve never said it out loud; even if this might be the first time I’m voicing those words even to myself.

“If you’d told us from day one,” I say, “that would have been the right way. That would have been the only painless way.”

“Not painless.” Mom shakes her head. “Never painless. Look at how it was already, without any of that added weight. The way you two grew apart; the way she acted out. Can you imagine how much worse it would have been if you both had known the truth? I dread to imagine what her teens would have been like. I don’t think we’d have been able to hang onto her till she finished high school. We’d have lost her long before.”

I sit with that. Speculation, alternative universes. None of us know what might have been, had things been different.

“You have to understand,” Mom says. “When Abigail was born, there was no such thing as DNA testing. It never in a million years occurred to us that one day you’d just be able to spit on a stick and everything would come crumbling down…” She looks at me. “Your father and I, it was a sacrifice for us, too, you know—having to hide something like that from you both. But we did what we thought was best. What we thought was the kindest thing.”

I drop my gaze from hers. Everything in the room seems too bright, lurching in and out of focus. Abigail. My sister. My sister and yet not my sister.

I remind myself that family isn’t blood, it isn’t mere genes. Of course she’s my sister, of course nothing about that has changed.

But if nothing has changed, why do I feel the ground shifting underneath me like this; upending itself forever?

“She did a DNA test, didn’t she?” I say. I was right. I must have been. The voucher on our hall table. I imagine a world in which Oliver and I had just used those stupid vouchers. We would have gotten our perfectly normal, predictable results, and my sister would never have discovered a secret that would turn our worlds upside down.

Imagine if Jeff had gotten Dinah a different anniversary present.

If Dinah had given those vouchers to someone else.

If I’d just thrown the damn things in the recycling.

Mom shifts in her seat.