The Dark Secret of Weatherend by John Bellairs

"Great! Mark the place with chalk and keep hunting. I haven't found any yet, but they may be cleverly—Hah! There's mine! Okay, we're really doing great!" Excitedly she fumbled in another pocket and came up with a squarish lump of white chalk. She marked the plugged hole with a small X and moved on to the next stone.
    It took Anthony and Miss Eells only about twenty minutes to locate all four holes. But by the time they were finished they felt as if they had been in this evil, airless place for hours. Anthony found that he was beginning to imagine things... at least he hoped that he was imagining them. He kept thinking that the carvings on the stones were moving. When he looked one way, he would see—out of the corner of his eye—something shifting, just a bit, on one of the other pillars. And more than ever now he found that he was having trouble breathing. It was getting harder and harder to fight down the panic. He wanted to leave; he wanted to leave now.
    "Come on, Miss Eells!" said Anthony, grabbing his friend by the arm. "We've marked all the holes, so let's just..." Anthony's voice trailed away. He saw, to his horror, that Miss Eells was just standing there with a glazed look on her face and her arms hanging limp at her sides.
    Anthony hesitated a moment. Then he seized her by the shoulder and shook her violently. "Hey, Miss Eells! What's the matter? Are you okay? Please say something!"
    "Wha... wha..." muttered Miss Eells thickly. "Who are... uh, I mean..." And with that she came to with a jolt. She looked about wildly—at the four grim dark stones, at the circle of shadowy trees, and at Anthony.
    "What... what was I doing?" she asked in a wondering, scared voice. "No, don't tell me—I don't want to know. You're right. We've got to get out. Are you ready?"
    Anthony nodded. He picked up the hockey stick and handed it to Miss Eells. Then the two of them plunged back into the cedar boughs. It was even harder going out than coming in, but somehow they made it. They reeled into the open, and after several nervous backward glances they headed toward the tennis court. When they got there, they did not stop but continued on till they got to the road. Emerson had told them that they were supposed to hide in the ruined building, but they'd had enough of enclosed spaces for now. They felt safer, somehow, just along the shoulder of the road.
    They waited. Fifteen minutes passed, then thirty, forty-five, and then a full hour. The shadows of the roadside trees grew longer and longer. Then the sun set behind the distant hills, and the sky grew darker. With a sick, tight feeling in his stomach Anthony knew that something had gone wrong.
    He peered anxiously up the winding drive. The white gravel of the road glimmered vaguely in the gathering darkness. When he spoke, his voice was a trembling whisper.
    "Miss Eells? Where... where's Emerson? What's wrong? How come he hasn't come back?"
    Miss Eells's face was pale and drawn. She bit her lip and shook her head despondently. "I don't know, Tony... I just don't know." She paced up and down a bit, and then lost her temper. She picked up a stone and threw it at the tennis-court fence. "Blast my brother!" she exclaimed in an angry, tearful voice. "He always knows what to do! You can't tell him anything, you can't warn him or make him cautious when there's every reason to be cautious. Em's got it all figured out! Oh, this is awful, Anthony! What on earth are we going to do?"
    Anthony looked around. He felt completely helpless. It was so dark that the tennis-court building was just a shadow, and he couldn't see the evil grove of trees at all. Once again panic was creeping over him. He wanted to get out of this awful, unnerving place, even though he knew that he ought to stay and try to help Emerson. He wanted to be brave, but he was terribly, terribly afraid.
    Once again he seized Miss Eells's arm and squeezed it. "We've got to go!" he hissed. "They'll get us if we don't!"
    Miss Eells