But 8001 was not. Close, just like the poem said.
But the poem didn’t ask for a prime number. It wanted aperfectnumber. A number that was equal to the sum of all its proper divisors. The closest perfect number to 8001 was 8128. The difference between 8001 and 8128 was 127. 127 was also a divisor of 8128.
Ivy quickly scribbled numbers on the page to check her math.
1 + 2 + 4 + 8 + 16 + 32 + 64 + 127 + 254 + 508 + 1016 + 2032 + 4064 = 8128.
127 was missing...
Ivy referred to the poem again.
Add the missing number, reveal the site.
Ivy added 127 to the tails of both GPS coordinates. 40.3299 became 40.3426. -74.6637 became -74.6510.
She shook her head.
“It’s not the right address. It’s not the Basin.”
Ivy grabbed her phone, typed in the new coordinates. As she did, Vaughn’s phone rang for what seemed like the hundredth time. He finally answered.
“Delaney! We’ve got another attack,” he shouted. “We—”
“It’s the Thomas Clarke House!” Ivy interrupted.
“What the fuck is that?” Vaughn said out of the corner of his mouth.
“It’s in the Princeton Battlefield.”
“Where—”
Ivy shoved her phone toward Vaughn. She could hear Delaney saying something, but couldn’t make out the words. He squinted as he read her screen.
“You hear that, Delaney? Battlefield State Park. Get there,now!” Vaughn ended the call. To Ivy, he said, “I know it. Hold on.” He wrenched the wheel, started back toward Fine Hall, raced up Alexander Street.
“Hurry,” Ivy said.
They had thirteen minutes left.
Somewhere in the back of Ivy’s head she thought,Hey, that’s a prime number, too.
?Chapter 61
Vaughn raced downMercer Road, saw the sign for the Princeton Battlefield State Park, and yanked the wheel so hard that two of the car’s tires lifted off the ground.
“Where to now?”
The dirt road curved a little before being flanked by sections of old wooden fences.
He was familiar with Battlefield State Park, but not the Clarke... whatever House. There was a fork up ahead. Left, a gravel road flanked by pines. Right, a little more open.
“Don’t know... right, I think,” Ivy said.
Vaughn went right.
It didn’t matter.
The road was short and looped back, connecting with the left fork, but there was no Clarke House.
