For a while, it seemed like it was. Whitney kept getting jobs, including a shoot for New York magazine, her biggest yet. Kirsten got a new hostessing gig at a very famous restaurant, and a cable TV commercial. If they weren't getting along, we didn't hear about it—instead of one weekly phone call where they passed the receiver between them, now they each called separately, Kirsten usually in the late morning, Whitney in the evenings. Then, about a week before they were due home for Christmas, we got a call during dinner.

"I'm sorry, what?" my mother said, the phone to her ear as she stood in the doorway that led from the kitchen to the dining room. My dad glanced over at her as she lifted her other hand, putting it over her free ear to hear better. "What did you say?"

"Gracie?" My dad pushed his chair back, getting to his feet. "What is it?"

My mom shook her head. "I don't know," she said, handing over the phone. "I can't…"

"Hello?" my dad said. "Who is this?… Oh… I see… Right… Well, that's a mistake, I'm sure… Hold on, I'll find the right information."

As he put the phone down, my mother said, "I couldn't understand her, what was she saying?"

"There's a problem with Whitney's insurance card," he told her. "Apparently she was at the hospital today."

"The hospital?" My mother's voice crept up to that scary, shaky octave that always made my own heart instantly start beating faster. "Is she all right? What happened?"

"I don't know," my dad said. "She's already been discharged, there's just a problem with the billing. I have to find her new card…"

As my dad went up to his office to look for it, my mom got back on the phone and tried to get information from the woman who'd called. Citing privacy reasons, though, she wouldn't tell much, only that Whitney had been brought in by ambulance that morning and left a few hours earlier. The minute my dad cleared up the billing issue, he called Kirsten and Whitney's apartment. Kirsten answered.

"I tried to tell you," was all she said. I could hear her voice from where I was sitting. "I tried."

"Put your sister on the phone," my father told her. "Now."

Whitney got on, and I could hear her talking quickly, her voice high and cheery, as my parents both leaned into the receiver, listening. Later, I'd get the story she told them: that it was no big deal, she'd just been really dehydrated—a result of an ongoing sinus infection—and fainted at a shoot. It sounded worse than it was, and the ambulance was just the result of someone panicking. She hadn't told us because she didn't want my mother to worry, and it really was nothing, nothing at all.

"Maybe I should come up there," my mother said. "Just to make sure."

No, Whitney said, there was no point, they'd be home for Christmas in two weeks, and that was all she needed, a real break, to get some sleep, and she'd be totally well again. "Are you sure?" my mother asked.

Yes. She was positive.

Before they hung up, my father asked to talk to Kirsten again. "Is your sister all right?" he asked her.

"No," Kirsten told him. "She's not."

But still, my mother didn't go. This was the biggest mystery, the one thing that, looking back, I could never quite figure out. For whatever reason, she chose to believe Whitney. It was a mistake.

When Whitney flew home for Christmas, she came alone, as Kirsten had to stay an additional few days for work. My dad went to the airport to pick her up, and my mom and I were in the kitchen, fixing dinner, when they returned. When I took my first glance at my sister, I couldn't believe my eyes.

She was so thin. Emaciated. It was obvious, even though she was wearing even baggier clothes than the last time I'd seen her, and more layers as well. Her eyes looked sunken in her face, and you could see all the tendons in her neck, moving like puppet strings whenever she turned her head. I just stared at her.

"Annabel," she said, annoyed. "Come give me a hug."

I put down the vegetable peeler I was holding, then moved tentatively across the room. As I wrapped my arms around her, I felt like I might break her, she felt so brittle. My father was standing behind her with her suitcase, and as I looked at his face I knew that he, too, was shocked by the change in her in only a month's time.

My mother did not acknowledge any of this, at least not out loud. Instead, as I let go of Whitney, she stepped forward, smiling, and pulled her close. "Oh, honey," she said. "You've had such a hard time."

As she leaned down over my mother's shoulder, Whitney slowly closed her eyes. The lids seemed almost translucent, and I felt a shudder run through me.

"We're going to get you well," my mother said, "starting right now. Go freshen up, and we'll sit down for dinner."

"Oh, I'm not hungry," Whitney said. "I ate while I was waiting for my plane."

"You did?" My mother looked hurt. She'd been cooking all day. "Well, surely you can at least manage some vegetable soup. I made it specially for you, and it's just what you need to get your immune system up."

"Really, I just want to sleep," Whitney said. "I'm so tired."

My mom glanced at my dad, who was still looking at Whitney, his face serious. "Well, okay, then maybe you should lie down for a while. You can eat when you wake up. Okay?"