donât like that rule!â
âI donât either, Benny, but we have to obey it.â
âOkay,â said Benny, taking Watchâs leash. âWeâll wait out here. Maybe weâll even catch Mr. Jones while youâre inside.â
Jessie went inside the post office and quickly found box 93. It was midway up a row of boxes and it could be seen through the front window of the post office.
She hurried back out and showed Benny which box it was. âWe can sit here under this tree and keep our eyes on the mailbox,â she said.
âOh, good,â said Benny, sitting down.
Jessie sat down next to Watch and Benny, and leaned back against the tree. For a little while, the post office was very busy as people stopped by on their way to work. Then fewer people came. Several customers went to check their mail, but no one went to box number 93.
Benny yawned. âIâm tired,â he said. âWeâve been here a long, long time.â
âHenry and Violet and Soo Lee will come soon,â said Jessie. She watched a stout woman in a baseball cap walk up to the wall of mailboxes. Her heart beat faster in excitement. Was Mr. Jones really Ms. Jones?
But the woman reached up high and opened a mailbox in the corner. Jessie leaned back against the tree again.
Watch, who had been taking a nap next to Benny, lifted his head and barked.
âWhat is it, boy?â asked Benny. âIs it Mr. Jones?â
âI think itâs just a squirrel Watch wants to chase,â said Jessie, pointing.
Sure enough, a squirrel who had been hopping over the ground scurried up a nearby tree. Watch laid his head back down on his front paws.
The time seemed to pass very, very slowly. Jessie was glad when she stood up to stretch and saw Henry and Violet and Soo Lee riding their bicycles down the sidewalk toward them.
âAny luck?â asked Henry as they came to a stop near the tree.
Jessie shook her head. She showed them where box 93 was located. âNo one has come near it,â she said. âIâm glad youâre here. We were getting tired.â
âAnd hungry,â said Benny.
âWell you can take a break now,â said Henry.
Violet set her backpack down on the ground and reached inside. âHere, Benny, I have an apple for you,â she said.
âThanks!â said Benny.
Just then Soo Lee grabbed Jessieâs arm. âLook!â she said.
They all looked in the direction Soo Lee was pointing. Someone wearing an overcoat, dark glasses, and gloves, with a hat pulled low over his eyes was walking toward the wall of mailboxes.
Violet gasped. âThat looks like the person who followed us that day!â
âAnd like the person Professor Madison described,â said Henry.
As they watched, the person reached out and opened box number 93!
âItâs him,â said Henry.
Mr. Jones took out a single letter and ripped it open hastily, throwing the envelope to the floor.
âHeâs littering,â said Benny indignantly.
âWait a minute, Benny. Letâs see what happens,â Jessie told her younger brother.
Mr. Jones read the letter. Then he folded it up and stuck it in his pocket, and began to walk very fast toward the post office door.
âWe can follow him,â Jessie said. âEverybody get your bicycles ready.â
But it was no use. When Mr. Jones got outside the post office, he went to a big, dark car parked in front of the post office. Before the Aldens could do anything, he had jumped inside and sped away.
The children jumped on their bicycles and rode as fast as they could after the car. But by the time theyâd gone a block, the car had disappeared from sight.
âOh, no!â said Henry. âWeâve lost him!â
âWeâll never solve this mystery!â cried Violet.
âYes, we will,â panted Jessie, pulling her bicycle to a stop. âRemember what Grandfather said about not