Merry glanced around wildly. There was nowhere to hide and no other exit. She turned and ran up the stairs into the body of the castle.

Around and around the narrow staircase, hugging the dank walls. Candles fixed to wall sconces, between pockets of darkness. She slunk from one to the next, heart and mind racing.

Who had followed her into the tunnel? And were they following her now? She had to find somewhere to hide. She hurried on up. She thought she could hear footsteps behind her but couldn’t be sure.

She came out into the servants’ area, in her time the cheery domain of Mrs Baskerville, outfitted with gleaming fridges and freezers and all the mod cons of a contemporary kitchen. Now it was dingy and gloomy. She could hear the clatter of plates and pans in the big old kitchen, and voices arguing in Welsh. She tiptoed past, on up the servants’ narrow staircase, up to the bedroom floors. The priest’s hole, she thought. She could wait in there till everyone went to sleep, then sneak out. She padded down the hallway, paused at the corner, breathing hard.

Male voices. Coming up the main staircase. Heading her way. She froze. Where now?

Then a door opened behind her. Trapping her. Merry wheeled around and came face-to-face with an elaborately dressed woman with blonde ringlets and a fancy lace head covering.

‘Why are you loitering?’ demanded the lady. Merry opened her mouth to say something when the woman cut in. ‘Follow me!’ she commanded, wrinkling her face with distaste as she eyed Merry up and down. Her gaze lingered, but only briefly, on Merry’s ruined eye. This was an age where physical imperfections, marrings and scarrings, pox marks and shrivelled limbs were not uncommon. ‘I’ve been waiting ages for a maid to come and see to my chamber pot,’ complained the woman, stalking back into her room.

Merry nodded her head and hurried in after her. In her linen shirt, tunic and shawl and bare feet, she must have looked like a particularly ragged servant. Just right for emptying chamber pots.

An unpleasant stink hit Merry. No wonder Little Miss Ringlets was so impatient.

‘Go on, then! Take it!’ ordered the woman.

Merry located the smell. Under the bed, of course. She hurried across the wooden floor and crouched down just as she heard other footsteps approach. And pause at the open door.

‘Everything to your liking, Lady Bess?’ asked a cool, clipped voice.

‘Why, perfectly fine, thank you, Lord de Courcy,’ replied the woman coquettishly.

‘Excellent. We shall see you for the feast, then. We have His Majesty’s favourite – spiced swan.’

‘Ooh, how delicious! Mine too,’ gushed the lady.

Merry kept her head bowed. She was terrified that the earl would recognize she was not one of his servants. Her hands trembled as she gripped the stinking chamber pot. She felt eyes on her back, waited, heart hammering. But the earl and his companion moved on. Merry blew out her breath, waiting until their voices had faded. She got up, nodded to the lady, and scurried out of the room.

The door shut behind her. Listening hard, adrenalin pumping, Merry crept along the empty hallway. She’d find somewhere to dump the bedpan, then hide in the priest’s hole. She crept past the watching portraits and realized with a jolt that most of the faces she was used to seeing were yet to be born. Their places were occupied by lushly woven tapestries.

She paused in front of what she thought was the right tapestry, pushed it aside and searched for the tiny ridge in the panelling. With the right amount of pressure, a concealed door would pop open, revealing the tiny hiding place inside. But there was no ridge. She searched under other tapestries and portraits, getting desperate as the seconds ticked by, but there was no priest’s hole. Then she realized: it hadn’t been built! Wouldn’t be built until Henry’s daughter, Elizabeth, became queen. She’d have to find somewhere else to hide, or try to get out now.

She rounded a corner, headed towards the servants’ staircase, then pulled up abruptly, nearly sloshing the contents of the chamber pot over herself. Someone was coming up. She could hear their footsteps, their laboured breath.

She turned and rushed back in the direction she had come, looking for a room to hide in. But each one seemed to be occupied. She could hear murmured conversations, some in English, others in French, coming through the heavy oak doors. She hurried on. There was just one room left at the far end of the hallway.

The red room. James had shown it to her once, when his parents were out – said it had always been occupied by the earl and countess. Merry paused, ear to the door. She heard nothing: no aristocratic conversation between husband and wife; no instructions to a servant; no industrious clattering of maids cleaning.

She opened the door, ducked inside, closed it. She blew out a breath and looked around.

The room was richly furnished, with lavish scarlet curtains and a heavily carved four-poster bed. The floor was sprinkled with lavender and rosemary.

Merry hurried across the scattered herbs, which released their scent into the air. She pushed the chamber pot deep under the bed. As she was straightening up, there was a knock on the door.

‘My Lady?’ called a voice.

Oh God, not again. Where to hide now? Under the bed with the chamber pot? No, she’d be spotted if the maid went to retrieve it, which, given the smell, she was bound to. She spun around wildly, spotted the wardrobe, tiptoed rapidly across the lavender and rosemary, ducked inside, and pulled the door shut just as the bedroom door opened.

Crouched in the darkness, she heard a voice curse in Welsh. There was a tiny crack in the wood. Merry put her eye to it and peered out. A maid was hauling out the chamber pot. Picking it up, she hurried out the way she’d come. Merry moved her hand to wipe a bead of sweat off her lip. Her fingers hit metal, a lever perhaps, because there was a slight click and something popped open against Merry’s arm. It was a drawer, velvet lined. Her fingers explored the soft surface. She felt rings, a selection, some smooth, some jewelled. One hooked itself on to her forefinger. She held it to the crack in the wood. In the darkness, it gleamed gold.

She thought of the book, of its promise of treasures. Her family could do with whatever treasures she could find. Surely it would be all right taking just this one . . . ?

She pushed the ring on to her finger.

A great gong sounded.

It was time for the royal feast.

She’d failed to find and free her ancestor. She had to believe he would be OK, that she shouldn’t in any case interfere with history more than she already had.

It was time to escape.