418.â
âOkay,â said Henrietta, and she plopped back onto the bed to watch as Henry began turning the knobs and pulling on them. âI hope itâs a map,â she added.
Henry had finished three and a half letters before she interrupted him for the first time.
âHow many are left, Henry?â
Henry stopped and thought. âIâve done 76. I canât subtract 76 from 418 in my head, but there are more than 300 left.â
He was done with five letters when she interrupted again.
âHenry, what are those other marks on the knobs?â
âWhat marks?â he asked.
âThose ones,â Henrietta said, and she sat up on her knees and licked her thumbs. Henry moved out of her way and watched her rub the knobs clean. The large arrows he had been using stuck out of the knobs. When Henrietta sat back down, Henry could see three more arrows on each knob. Much smaller and on the surface of the skirts only, they divided the knobs into quarters.
âThey look like compasses,â Henrietta said. âSee? The big arrow is how they do north on maps, and then thereâs south, east, and west. I bet there is a map in there. What else would be behind compass knobs?â
Henry didnât answer. He slumped.
âWhatâs wrong?â Henrietta asked.
Henry flopped all the way back on the bed and clicked his teeth. âWeâll never get it open.â
âWe wonât? Why not?â she asked. âStop grinding your teeth. There canât be that many left.â
âThereâs way more. I donât even know how to find out how many more. With four pointers on each knob, there could be thousands of combinations.â
âOh,â she said. âMaybe we should go to bed. We can figure it out tomorrow.â
âYeah. We should go to bed.â He looked at his blanket. âBut first I should clean this up.â
Henrietta stood and stretched. âJust take it downstairs and shake it outside.â
Henry pulled his blanket up by its four corners and slung it over his shoulder like a sack. Then the two of them left his room and crept carefully down the stairs. They reached the girlsâ room, whispered good night, and Henrietta hurried to her bunk. Henry continued downstairs to the mudroom. Stepping outside, he decided to go a little ways from the house so nobody would see plaster on the lawn. His bare feet were swallowed by the cool grass, but he didnât notice. He was staring up at an enormous sky, heavily dusted with stars. A glaring two-thirds of a moon sat just above the horizon. He made his way down to the barn, went around the side, shook out his blanket, and sat down.
Henry had never heard of such a thing as a forgotten door. Back at school, he never would have believed such things existed. But here was different. There was something strange about here. He felt just like he had when heâd found out that kids his age donât ride in car seats and that boys pee standing up. He remembered unpacking his bags at boarding school while his roommate watched. His roommate had asked him what the helmet was for, and Henry had suddenly had the suspicious sensation that he had been kept in the dark, that the world was off behaving in one way while he, Henry, wore a helmet. He had barely prevented himself from answering his roommate honestly. The words âItâs a helmet my mom bought me to wear in PEâ were replaced with âItâs for racing. I donât think Iâll need it here.â
Whatever was going on inside the wall in his room was much bigger than finding out that other boys didnât have to wear helmets. If there really were forgotten doors and secret cities, and maps and books to tell you how to find them, then he needed to know. He looked around at the tall, dew-chilly grass and for a moment didnât see grass. Instead, he saw millions of slender green blades made of sunlight and air, thick on the