She got a tissue out of her bag and picked the thing up for closer inspection; then she went around, got behind the wheel, and laid it out on the seat next to her. When she hit the ignition, she did flinch—in the event the Audi burst into flames—except her heart rate settled fast. But come on, she was an innocent bystander when it came to whatever was going on with Isaac, and she had to imagine that an American civilian on American soil was not the kind of collateral damage the U.S. government wanted to deal with.

As she drove over to Beacon Hill, she put a call in to her father, and when she got voice mail, she tried to leave a message, but what could she say given that she didn’t know who was listening? She ended up deleting the fits and starts and figured he’d see the missed alert on his phone and get back in touch with her.

At home on Louisburg Square, she parked in her spot against the fence and looked around through the car windows. Who was watching her? And from where?

No wonder Isaac had been twitchy. The idea of getting from her Audi to her front door made her wish she had a Kevlar vest on.

Grabbing her purse and palming the Life Alert with the tissue, she got out and hurried over—except as she got closer to her house, she slowed. On the lantern, wrapped tightly around the base, was another strip of white cloth.

Pivoting fast, she stared up at all the brick buildings and wished she could see inside them.

She was not alone anywhere she went, was she.

As her heart got back on the Pony Express and her blood rushed through her veins and her brain, she ducked into her front door, disengaged the big alarm, and put the Life Alert on the breakfront. Dropping her bag, she quickly shut up the ADT’s beeping, and then leaned out of the house only long enough to pull the cloth free.

One, two, three: she shut herself in, locked the door and reengaged the monster system—something that she never did in the daytime when she was at home.

With grim purpose, she went into the kitchen with her bag and put everything on the counter: the business card, the pieces of cloth, and the transistor. All of which she was careful to handle with a tissue.

The two sections of fabric were identical and had clearly been ripped off the same source—and she had a feeling where they were from. Isaac’s muscle shirt.

What do you want to bet it was a signal that he was—

As her cell phone went off, she yelped and nearly blew out of her shoes. When she checked who it was, she answered and didn’t waste time.

“Dad . . . we need to talk.”