So I had seven hours, give or take a few minutes. Plenty of time to zip out to the suburbs to visit my sister, Gwen, as long as I took a tub of coffee along for the ride. Gwen had made Halloween costumes for her kids and wanted to show them to me before, as she put it, “the little brutes trash them.” A quick phone call, and she said now would be perfect.

I didn’t want to drive the Jag, not with that whiny noise. Going by commuter rail out to Needham and back, I could return to Boston by nine, pick up my supplies, and get over to Frank’s condo in the North End before ten. I was overdue for a visit to my sister’s. So I’d chat with Gwen, oohand ahh over the kids, and let her talk me into staying for supper. Gwen was a terrific cook. My own efforts in the kitchen tended toward the frozen-dinner-and-microwave approach.

I caught the train at South Station, right on time, and dozed a bit on the ride. After a quick forty minutes, I was waving to Gwen as I got off at Needham Heights.

Most people are surprised to learn that Gwen and I are sisters. It’s not that there’s no family resemblance—you can see that if you look for it, in our amber eyes and heart-shaped faces. It’s more that our lifestyles make us look like we come from different planets. I favor wash-n-wear hair and leather jeans. Gwen looks exactly like the role she’s chosen: a stay-at-home mom in a pricey Boston suburb. Her chinos and polo shirts are designer brands, and she wears her chin-length auburn hair in one of those elegantly casual styles that requires twice-a-week maintenance at a salon. She probably spends as much on her hair each month as I spend on rent—and even with a roommate, my apartment isn’t cheap. And although Gwen isn’t exactly overweight, she plumped up some with the birth of each child: Maria, a ten-year-old tree-climber; Zachary, a frighteningly energetic five-year-old; and Justin, still the baby at two. Great kids. Gwen, of course, believed they were the most adorable children on Earth. As their aunt, I tended to agree.

“Where are the kids?” I asked as I strapped myself into the minivan. It was rare to see Gwen without a munchkin or three in tow.

“They’re at the neighbors’, putting on their costumes. I think they plan to scare you when you arrive.”

“Thanks for the warning. For your kids, I’ll go all the way to terrified.”

Gwen smiled and navigated the minivan through the maze of suburban streets. I could always find my way around a city, but put me in suburbia, among all those green lawns and picket fences, and I got hopelessly lost.

Gwen lived in a Cape Cod-style house in the Birds Hill neighborhood. The area was developed after World War II, filled with compact ranches and Capes where returning veterans and their sweethearts raised their families. The next generation, though, seemed to demand more from its homes. Every time I came out here, another ranch house had been razed to make room for a mini mansion. Scaled-down faux French châteaux and English manor houses loomed over the more modest homes that had given Birds Hill its family feel. If you asked me, the huge houses looked silly on their quarter-acre lots. Somehow, though, I didn’t think the owners of those million-dollar homes were falling over each other to get my opinion.

Gwen’s block, at least, still had that cozy neighborhood feel. It was the kind of place where everybody knew their neighbors and went to monthly potluck dinners. We pulled into the driveway, and a costumed figure burst from behind the garage, where he’d obviously been watching for us.

“Arrrrh!” yelled Zachary. “Ahoy, mateys!” He was the cutest—I mean fiercest—pint-sized pirate I’d ever seen. He wore a black tricornered hat, an eye patch, and a blue coat with silver buttons. A drawn-on moustache curled unsteadily over his mouth. The stuffed parrot perched on his shoulder wobbled as he waved his cutlass.

“Zack, be careful with that,” warned his mother.

I cowered in my seat. “You’re not going to make us walk the plank, are you?”

Zack giggled with delight and nodded vigorously. He jumped up and down, chanting, “Walk the plank! Walk the plank!”

Gwen got out and went around the front of the van. She put a hand on Zack’s parrot-free shoulder and held it there until he stopped jumping. “If you keep telling Aunt Vicky you’re going to make her walk the plank, she won’t get out of the car.”

“Oh.” Zack considered this. “Okay, Aunt Vicky, I won’t make you walk the plank.” His eyes sparkled with mischief. “This time.”

“Thanks, Captain.” I climbed down from my seat. “That’s a terrific costume you’ve got there.”

“Mommy made it.” A movement in the next yard caught Zack’s eye, and he took off, yelling “Ahoy! Ahoy!”

“Zack!” yelled Gwen. “If you ruin your costume, you can’t go trick-or-treating!”

“Okaaaaay, Mommm . . .” His voice faded in the distance.

Gwen stood with her hands on her hips, smiling in the direction he’d disappeared. “Now where are those other two?”

“Come on, Justin.” Maria’s voice came around the corner of the garage. A second later, she appeared, leading her baby brother by the hand. Justin, dressed as a teddy bear, toddled along unsteadily, his eyes round. When he saw me, he smiled that heart-melting baby smile, held out his arms, and said, “Twick or tweat, Aunt Vicky!”

Maria giggled. “Not yet, silly. Trick-or-treating’s not ’til Friday.” Maria had her long sandy hair pulled back in a pony-tail; she wore a black turtleneck sweater and black jeans.

“What are you, Maria?” I asked.

She glanced at her mom, a little nervously. Gwen said, “Why aren’t you wearing your costume?”

“It took forever to get Justin ready, Mom.”

“Well, go put yours on now.” Gwen picked up Justin, perching him on her hip, while Maria zoomed off around the corner of the house.

“Wait’ll you see her costume,” Gwen said. “It took me a week to make it. She’s a fairy princess bride. It was really hard getting the wings right.”

Justin stared at me with wide eyes. “Twick or tweat?” he tried again.

I patted my pockets. “Sorry, Justin, I’m fresh out of candy.” I really should try to remember to pack a few lollipops or something when I go to see Gwen’s kids.

Maria peeked around the corner of the garage, then stepped out. She didn’t look like any fairy princess bride I’d ever seen, but then I didn’t have a lot of experience with such things. She was still dressed all in black, but she’d added a double holster with two toy guns and a plastic dagger stuck in the belt, and there was something on the back of her head.

Gwen stared at her daughter as Maria walked shyly toward us. When she got to the edge of the driveway, she turned around, showing the plastic lion mask she wore on the back of her head.

“Maria, what on earth—?” Gwen began.

The girl turned back to face us, beaming. “I made it myself, Mom. Don’t you get it? I’m Aunt Vicky.”

Uh-oh.

The enthusiasm in Maria’s voice picked up as she explained. “See, on this side, I’m a demon fighter.” She drew a gun, made shooting motions, then holstered it. She turned again to reveal the lion mask. “And on this side, I’m a shapeshifter. Pretty cool, huh? I found the mask at the church thrift store, and that gave me the idea.”

“What about your bride costume?” Gwen’s voice sounded strangled.

“Oh, I gave it to Brittany.” Brittany was Maria’s best friend. “She likes that girly stuff.”

“Young lady, you are not going to—” Gwen glanced sideways at me. “We’ll talk about this later. Now go change Justin back into his play clothes.”

Maria’s face crumpled, and a tear leaked from the corner of her eye. She blinked rapidly, then turned to me. The elastic from her mask made a line across her forehead. “You like my costume, don’t you, Aunt Vicky?”

Oh, boy. How was I gonna answer this one? My options seemed to be upset Maria or make Gwen mad.

“It’s a great compliment, Maria. I’m really flattered.”

Maria beamed at me, then flashed her mom a look that was half triumphant and half an acknowledgment that she was in big trouble. She lifted Justin out of Gwen’s arms and led him around the garage toward the back door. Justin gazed back at me, looking like he was still trying to figure out why the magic words had failed to produce any candy.

Gwen watched them go, arms folded, her mouth a tight line. Then she turned and marched up the front steps.

Wonderful. I’d been here five minutes and had already caused an argument. Ah, the joys of family.

I SAT IN MY SISTER’S LIVING ROOM—COLONIAL-STYLE, a Wedgwood blue sofa, two beige wing chairs by the fireplace—while Gwen banged things around in the kitchen. She said she was making coffee, but mostly she seemed to be taking her feelings out on her appliances. A cupboard door slammed hard, and the floor vibrated under my feet.

I knew why Gwen was angry about Maria’s self-made costume, and I couldn’t blame her. Well, I couldblame her, but I could also understand. Ever since Gwen’s firstborn had turned out to be a girl, she’d been terrified that the child would grow up to become a shapeshifter. Just like Aunt Vicky.

Among the Cerddorion, only females have the ability to shift. And that ability manifests with the onset of puberty. With each year that went by, Gwen grew a little more afraid that Maria was going to turn out to be one of the monsters.

Well, not a monster, not really. A demi-human. That was the official classification for Gwen and me both. The only difference was that I was classified as demi-human (active) and Gwen as demi-human (inactive). That meant she no longer had the ability to shift; she just had some funky stuff going on with her DNA that could create more demi-humans down the line. So Gwen had all the rights of any norm—she could vote, travel freely, live outside Deadtown—and I had all the restrictions of a PA.

Gwen hadn’t always been ashamed of what we are. She’s four years older than me, and she’d started shifting before I could. And she loved it. In fact, hardly a month went by when she didn’t use up all three shifts. PAs weren’t out at that time, so she had to be discreet, but Dad encouraged her to experiment. Even Mom, always the worrier, remembered the early thrill of shifting and loosened the tight leash she normally kept on us girls.