Her fingers encountered something cold and hard. Philomena flicked at it, and a key clattered to the floor. The noise resounded like a thunderclap and she flinched. For a count of ten, she held her breath and rubbed her fingertips together. They were clean. The lintel was quite free from dust. Someone had been here recently.

She slid the key into the lock. It turned without resistance and the door swung open. Moving fast, she stepped inside and closed the door. Now, she could not go back. This was the forbidden East Wing. She held the lamp high to light the way. A flight of stairs spiralled upwards, narrowing as it turned. The light sputtered as her hand trembled. She tiptoed on the wood of the stairway, trying to make no sound, listening all the while for danger.

At a turn on the stairs was a small window. Philomena squinted through into the darkness. In the moonlight, she made out the shapes of the trees in the wood. Sensations flooded back. Over there, Lord Thatcham had clasped her to him. Her lip quivered. Why had he been so cruel? He had treated her like a toy designed for his selfish pleasure.

She grew hot with shame. She had not protested for long moments as she cherished each new sensation. Had he noticed? She brushed the thought aside. She had no time to waste. She was on the brink of discovering Lord Thatcham’s guilty secret. The arrogant man deserved a lesson.

A few more steps took Philomena to a low doorway set in a turn of the stairs. She tried the handle. It turned with ease, and the heavy oak door creaked open. She grimaced.

This was the moment. It took a few seconds to gather her resolve. Inside this room, hidden from the rest of the Hall, was the evidence of Lord Thatcham’s guilt. Philomena stood tall, lifted her chin and stepped boldly inside.

An eerie glow lit the sparsely furnished room. A line of tables marched along the centre of the room. In the strange light, Philomena saw a set of rough wooden shelves, an old, well-used armchair and a plain stool. Leather bound books lay in heaps on one of the tables, near to a small reading light. One was open, the pages covered in diagrams. A second table held a brown wooden box, about ten inches long and seven inches high, and a mirror covered the entire surface of a third. Rows of opaque glass jars in blue and red lined the shelves.