Eek! A critique! Of a YA myster-eeeeeeeee

Okay, people, help a girl out. This book is becoming the bane of my existence. I have no idea what works, what doesn't. If my narrative voice is any good, if the characters are compelling. I know nothing.

In this scene: Troy, nearly 18, is lamenting the fact that his estranged sister, who he hasn't seen in three years, recently stood him up.

Also, this is set in 1995 -- hence the answering machine and handwritten note.

Gracias in advance.

**

Troy returned home to a note in Jerry’s handwriting and a twenty dollar bill tacked up on the fridge with a magnet.
Client dinner. Order a pizza. Invite Caitlyn over. Her parents are in Aruba.
Only Troy’s parents would encourage he hang out with the pretty blonde neighbor girl without any adult supervision. But then again, Troy’s parents knew him. Caitlyn, however, didn’t. He’d eat the pizza alone.
He ran upstairs to his bedroom, dropped his car keys on his nightstand, and shucked off his boots. The button on his answering machine blinked. Troy exhaled. It had to be Miranda. He was already bracing for her excuses.
Sorry, I forgot the time.
They changed my schedule at work and I couldn’t call you.
I overslept.
I’m in a ditch somewhere.
He pressed the button.
“Hey Troy, Coach Shipman calling. I saw you at the open meet…” Troy deleted the message.
That was it.
Nothing from Miranda. He’d give her a few more days before he swore off her forever. Like she did to him the day she left.
“Don’t worry, little bro. I'll be back one day,” Miranda had said. She rubbed the top of his head, even though he was taller than her at this point. Three years apart, they were often mistaken for twins.
Dressed in ripped jeans, a sweatshirt, and armed with a duffle bag, Miranda had one foot out her window before Troy caught her.
“You weren’t going to say goodbye?” he asked.
She glanced away, toward the street. “You know how I hate the emotional stuff. Besides, I didn’t want you ratting me out to Mom and Jerry.”
“I wouldn’t do that.” He was desperate to pull her inside the window, tie her up, make her stay. He’d been out of Hulbert a year and things hadn’t felt any better. “Can’t you just move nearby? You don’t have to live here.”
She shook her head. Dark strands of hair got caught in her mouth, but she was holding on so precariously to the window ledge, she couldn’t risk letting go to smooth back her hair. “I want to see places. I’m itchy.”
Troy quickly unclipped the cross from his neck and fastened it above the collar of her shirt. “Take it. You can always pawn it if you need the cash.”
Miranda smiled softly. “Thanks.” She looked down before swinging out her other leg and dropping to the ground, landing with a thud. It was an easy eight-foot drop.
Miranda was fearless. Reckless. Impulsive. Troy used to be like that.
“I’ll send you postcards,” she whispered up to him. Then she took off down the long driveway, disappearing into the dark.
Troy stared out the open window for awhile, ignoring the chill, adding Miranda to the list of people lost to him.
Three years later, she intruded into his life with a phone call. Made him drive up to Cohosh only to disappear again, probably halfway to Nashville or Atlanta. Maybe she was on a plane headed to Europe. But, she led him to believe she’d be there to see him.
Miranda was still reckless.