“I have to run upstairs and put my swimsuit on. It will only take a minute.” I glance up at Mom.

“I can’t wait for you,” she says tersely. “I’ve got to be there early. I’m presenting this morning. I’ve been texting you. Why didn’t you answer?”

I decide to be petulant. “Did you ever think it might be nice, Mother, to ask me if I wanted to watch my little sister today? Because it feels like you’re assuming I have no life.”

“What?” She seems puzzled more than anything else. I have never complained about Abby before. “Look, I don’t have time to—”

“Then when will you have time?” I interject.

She shakes her head, baffled by the sudden appearance of Uncooperative-Ada. “What’s going on with you?”

I close my eyes against the image of the white robe. “Nothing. I’m just sick of you treating me like the hired help. Always me, of course, and not Afton.”

“Afton’s still asleep.” She’s not, though. She checked on me in the bathroom. But Mom obviously doesn’t know that.

“Let me guess: she was out late last night,” I say instead of correcting her. “You have no idea where, or what she was doing.”

“She’s eighteen,” Mom says. “She can do what she wants. She’s an adult.”

“Right. And I’m sixteen, so I’m a child, and I’m stuck doing child labor.”

Mom’s eyes flicker to Nick, who is attempting to inconspicuously edge his way over to the stairs. Me being a brat to my brilliant mother is making him uncomfortable. “Hello,” Mom says.

He freezes. “Hello, Dr. Bloom. Uh, nice day to—”

But she’s done with pleasantries. And also, apparently, with my sass. She shoves Abby’s hand into mine. “I don’t have time for you to decide to be a teenager right now. I won’t be back for lunch. Money’s on the bedside table. Don’t forget to reapply sunscreen every two hours. I don’t want you two getting burned.”

I nod numbly. “Yeah. Okay.”

Mom hurries away in the direction of the tram, looking at her phone the whole time, stepping carefully around the tourists.

“O-kay. I’ll see you later, Ada,” Nick says.

“I couldn’t be too compliant, could I?” I say by way of explanation.

He smiles, nods, but still ducks toward the stairs instead of the elevator.

I feel a tug on my arm. “Don’t you want to go swimming with me?” Abby asks in a small voice. “Don’t you like me?”

I kneel down next to her. “I love you, Abby-cakes. You know that. You are, by far, my favorite sister.”

“But you wanted to give me to Afton,” she says accusingly. Her bottom lip trembles. “And Afton always tries to give me away, too!”