Early Saturday morning, Samantha’s parents were getting ready for the EPE—the Exotic Pet Expo—in Tacoma. It was an all-day event, so they didn’t expect to be home until evening. Mrs. Spinner was going to deliver her popular lecture “Nutrition for Extremely Large Lizards.” Mr. Spinner was going along to check out the very latest in light-up dog toys.
They were bringing Dennis with them. Pets were always welcome on the EPE exhibit floor. Just not in the food court.
“Be good, you two,” their father told Samantha and Nipper as he carried lunches and a spare umbrella to the car. “Don’t break anything while we’re gone.”
Both kids knew he meant lamps and lightbulbs when he said that.
“And, Nipper,” their mother added, “you really should stay away from that Snoddgrass girl. She’s not very nice to you.”
Neither parent said anything about not going out and investigating a secret map to landmarks all over the world—which is exactly what Samantha and Nipper were planning to do.
As the car pulled away down the drive, Samantha noticed Dennis through the rear window. His bejeweled collar sparkled in the sun. He had a weird expression on his face, as if he was hearing a strange noise. Or maybe he was just thinking about squirrels or waffles.
The car turned and disappeared down the street. Samantha and Nipper sprang into action. They had at least eight hours until their parents would return, and this was their chance to see if the Plans were real. Within minutes, they were out the door.
They hurried past the Snoddgrass lair, then past two more houses, and reached the end of the block.
A blue mailbox stood at the corner of Prospect Street and Thirteenth Avenue.
Samantha and Nipper had walked past it hundreds of times. And just like this time, there didn’t seem to be anything special about it.
They both stared at the metal box with the round top. A label on the front said “US Mail.” There was a faded chalk drawing on the sidewalk of a kid with a sword through his head. Nipper had been there when Missy Snoddgrass drew that a few days ago. She’d ordered him to act it out, but he ran away.
“What exactly are we looking for?” Nipper asked.
“I haven’t the foggiest idea,” Samantha said, and shrugged.
She walked slowly around the mailbox, looking for anything unusual. When she’d completed her circle, she opened the umbrella and gestured to her brother.
“Help me look,” she said.
Nipper took out the magnifying glass and raised it to the umbrella. Together, they examined the little drawing of the mailbox with the number 3 written on it.
Samantha closed the umbrella, and they began to search the mailbox for buttons or a lever or anything unusual. Then they looked for anything that said “3.” They found nothing.
Samantha reached out and pulled down on the handle of the mailbox flap. The opening was at her eye level, so she peeked inside.
“Nothing,” she said, squinting into the dark. “It’s just a regular old mailbox.”
“Let me have a look,” said Nipper, pushing her out of the way and standing on tiptoe.
Momentarily the same height as his big sister, he peered into the mailbox slot as well and saw…nothing.
“I told you there wasn’t anything to see,” said Samantha, holding the flap open and gesturing at it with her other hand.
She let the mailbox close and something deep inside made a loud metal click. Samantha and Nipper looked at each other. A whirring noise kicked in.
Sister and brother jumped back, sure that something was about to happen. They stood on the sidewalk and watched the mailbox carefully.
“Did you break it?” asked Nipper.
“No,” said Samantha. “But I think I know what the number three means.”
She stepped forward and grabbed the handle again, pulling the flap down and holding it open for at least ten seconds before letting go. She did this twice, and, each time, a click and a whirr followed. Then she hopped backward to stand beside her brother on the sidewalk.
There was a rumbling, clanking noise, as if something very heavy was being unlocked. Then they heard a loud hiss and felt a gust of air rushing past them. With a low mechanical murmur, the ground beneath the mailbox moved. A section of pavement with the mailbox on top rose out of the ground, revealing a large rectangular shape underneath.