The British got closer, and the colonists waited and waited—and then fired. They made every shot count.

However, the British attacked three times, and the high ground didn’t save the colonists. They retreated from the top of Breed’s Hill, and American casualties were bad—140 killed, and more than 300 wounded. But British losses were huge, the most soldiers lost during any single battle of the whole Revolutionary War: 226 dead and 828 wounded.

Those terrible losses made the British change their plans about taking control of Dorchester Heights—which was the really important high ground above Boston. And several months later, who took command of the Heights? General George Washington—and then American cannons started pounding the British. The patriots pushed the English completely out of Boston, and finally went on to win the whole war.

Ben counted off the last five steps up to the landing. Winning America’s independence hadn’t been easy. And this war, today? At the moment, he felt outnumbered and outgunned. Victory seemed a long way off.

When they came out of the stairwell onto the third floor, Jill said, “You’re dangerously quiet all of a sudden—what’re you thinking about?”

Ben shrugged. “Warfare, tactics, espionage, casualties—fun stuff like that.”

He stopped at his locker and began dialing the combination.

“Do you have a plan for today?” Jill asked.

He nodded. “Yup. I plan to eat two pieces of chocolate cake at lunch. And we’ve also got to come up with a way to check out that new space.”

“You mean, the rathole?” said Jill.

Ben smiled as he pulled the locker open. “Yeah, that’s what I—”

The next word stuck in his throat. He stared, his eyes wide.

“What?” said Jill. She moved and looked over his shoulder.

A scrap of paper was taped onto the inside of the metal door, a note scrawled in pencil:

Not bad–for an amateur

Ben wasn’t looking at the note. He was looking at the tape. The paper was stuck to the locker door with black electrical tape, six pieces of it, and each piece was a circle about as big as a penny. He pointed at one.

“Lyman found the fake sensor.”

“I don’t care what he found!” Jill hissed. “Nothing gives him the right to open your locker—you have to report this!”

Ben pulled out his little camera and snapped a picture of the note. Then he reached into his locker, got a book of Jack London stories, and slapped the door shut.

“You’re just leaving it there?” she said.

He nodded grimly. “To remind us what we’re up against. Keep thinking about our next moves, okay? Especially since he knows we’re onto his alarm system. See you in math.”

Ben walked off quickly before Jill could study his face.

He went down the long hall, past the compass rose, past the tall portrait of Captain Oakes, past the cache where they’d found the big key and the list of safeguards. He turned the corner and hurried into the north stairwell—and there was Lyman on the third-floor landing, tall and thin, leaning on the handle of a dust mop. When he saw Ben, his long face broke into a crooked smile.