The Hidden Treasure by Lucy Ellen Guernsey

Jack went to his room, where his lamp was already lighted, and taking his beloved books from their usual hiding-place, he began to think what he should do with them. They were not many. There was first and dearest of all, the New Testament with Tyndale's notes, which had been given him by Master Fleming; then his Greek Testament; the Prophecy of Isaiah which he had brought from Mary Brent's house, and two or three small tracts and treatises. These last he read carefully through, once more, and then burned; but he could not bring his mind to burn his Bible.

There was a certain little cupboard in the wall, concealed by a sliding panel, which Jack had discovered by accident some few years before, and of the existence of which he had never heard any one speak. He had concealed his discovery with a boy's fancy for mystery, and now it was to serve a good purpose. He opened it and placed his books therein, all but his Greek Testament, which he thought he might safely reserve. He then closed the panel, and pushed his desk against it, and he had just finished these arrangements when he heard some one open his door.