‘Is it worth it, Katherine?’

My breath caught as her hand brushed imperceptibly against my shoulder, in the lightest of warnings.

‘Who is to know?’ I replied lightly, deliberately obscure. By now I was beyond denying what was clearly the talk of the household. It had been an exhausting evening of disturbing revelation, leaving me with no wish to defend myself yet again; the condemnation of my sister had been quite enough, and now wounded by this new injury, I was beyond explanation.

‘I’ll not decry true love, if that is what it is between you,’ Lady Alice pursued without demur. ‘But you must know the risk is great. What will she say when she finds out?’ The lady’s gaze slid to Constanza, much as mine had done. ‘Which she will. In fact, after that dramatic performance, I think we can safely assume that she has more than an inkling. You must be wary.’

Oh, I was wary. And I was afraid. Even though I knew it would deepen my hurt, I forced myself to watch as the Duke took Constanza’s hand and led her from the chamber in the direction of their own accommodations.

‘As I live and breathe, Katherine, all I see is doom and gloom in this marriage,’ Lady Alice remarked before we parted for the night. ‘As well as heartbreak for you.’ She looked as if she might have said more, but closed her lips with purpose, for which I was grateful.

My heart shivered as if I felt a grinning manifestation of ruin that loomed at the head of the bed in which it was clear that I must sleep alone that night. How tender the Duke had been towards his wife at the end, how gentle, while she had responded with an affection we rarely saw. As she drew him closer towards her, I was left to acknowledge the increasing vulnerability of my position. The steely challenge in Constanza’s cleverly constructed campaign informed me that she knew exactly what she was doing.

My future was suddenly all clouded.

Who was to know what steps the victorious Constanza would demand from the Duke in return for the promised crown of Castile? My banishment could be the first of the coins the Duchess would see fit to demand. A chill breath whispered along my skin as I combed and braided my hair that night. It was not in the character of the Queen of Castile to remain silent and unresponsive for long, and the Duke, in gratitude, might bow in acquiescence.

A choice between me, a woman who provided a brief slaking of lust, and the royal claimant to the might of Castile? Of course the Duke would cleave to his wife. Even if he did love me, such a superficial emotion could hardly weigh in the balance. In the depths of my heart I acknowledged it. How could I blame the Duke for pursuing a prince’s ambition? A mistress was transitory, easily discarded.

Was the Duke’s decision to appoint me magistra to shield me from humiliation in service to Constanza? Or was it to shield Constanza? Was it marital respect that she roused in him, or had it indeed become a more fervent emotion?

My mind tripped over the lines sung so aptly by the Duke’s squire:

‘Love like heat and cold pierces and then is gone;

Jealousy when it strikes sticks in the marrowbone.’

Jealousy infused my bones. Constanza, I accepted during that long night, was a foe of merit. My decision to leave my son and return to my lover, that choice with all its heart-searching, was transformed into dross. I should never have allowed myself to dream of a future with the Duke of Lancaster. What fools love can make of us. How blind it can make us. All I had done was drag closer the promise of ultimate degradation.

Of course I blamed the Duke—what woman would not, faced with such evidence of disaffection? And like all women struck with jealousy, I took my revenge in the only manner open to a mistress in so public a place as The Savoy.

With all my seeds of doubt blossoming into bitter fruit I determined that I would not share his bed.

‘I cannot. I am unwell.’

I felt that my smile was brittle enough to scratch the surface of my looking glass as I made the excuse of all womanhood.

When, the household sleeping, he came to my chamber, it was to find my door barred. Tense with dismay that I had been thrown to the wolves, with Constanza’s star in the ascendant, it was the only action I could take. That I was standing within, palms flat against the wood, my heart torn with longing as he knocked lightly, he would never know.

How unworthy my thoughts were, how heavy my regret as his footsteps receded.

My conduct from day to day, hour to hour, remained impeccable. I curtsied. I spoke calmly when addressed. I sat at table. I fulfilled my duties to the ducal children. I laughed and sang and played games. I reverted to the epitome of the dignified, composed and dutiful widow, the Lady of Kettlethorpe.

And all the time I shivered with apprehension.

What are you trying to prove? I asked myself more than once as I made very sure that I was never alone in proximity to the Duke, who was beginning to wear the vexed restlessness of King Edward’s caged lion at the Tower.

I knew the answer. I wanted to know that the Duke’s desire for me was still as vitally alive as when I had given birth to his son. I needed to know from his own lips. If my star was in decline, I must know it, for my own self-respect. How demeaning to remain the ducal mistress in the face of the Duke’s flagging interest—for I had been forced to accept that, for him, love was never an issue. I admitted, with clear-eyed despair, that I was pushing our strained relationship to a shattering climax.

Would I regret it? Would it not be better to cling to the crumbs of the Duke’s need for me in his life rather than reject the whole banquet?

I did not think so. My deliberate isolation was as much a challenge to the Duke as Constanza’s malicious little game had been to me. It was the only manner in which I could express my fear, for to shout it from The Savoy gatehouse might give satisfaction, but was not seemly. I knew full well, as I had always done, that whereas I offered the Duke love’s coin of shining gold, his return to me was of a lesser value.

Duchess Constanza smiled often and kept the Duke frequent company.

‘Madame de Swynford! A moment of your time!’

The Duke hunted me down in the Great Hall, and stopped me by the simple strategy of announcing my name, giving me no alternative—other than discourteous flight— but to await his approach with the loping stride akin to one of the fit hunting dogs at his side.

‘So that we can hold a conversation without undue emotion,’ he announced as he halted within feet of me. ‘Are we not in the public eye here?’ He smiled, but I was not deceived. This might just be the termination that I had precipitated.

‘Yes, my lord?’ I curtsied neatly, every muscle braced. There would be no hiding for me here, as he well knew.

‘Yes, my lady,’ he returned with languid grace as he handed me a fine leather-bound volume, as if that might be the reason for our meeting. I tried to read his expression, and failed, but the tightly pressed lips were not friendly.

‘Let us talk siege warfare, Lady Katherine,’ he suggested, launching into an unnervingly smooth discourse. ‘Tell me what it is that has lowered the portcullis between us. I get the impression that I must lay siege to encourage you to raise it. I did not think that I was the enemy.’

‘You are not my enemy, my lord.’

All my senses told me that I must keep my wits keen. In this mood, the sardonic Duke was unpredictable. What’s more, he was confident. I could see it in the flare of his nostrils, the glitter in his eyes. He expected to win this encounter. I raised my chin, prepared to resist. There would be no easy victory here for either of us.

‘So why, madam, have you built your defences against me?’ the Duke pursued, showing his teeth in a smile that was not a smile, for the sake of a passing servant.

‘Because I am uncertain of my position, sir.’

‘I thought I had made your position clear.’ His brows rose, his tone was acerbic. He knew I was fencing with him, while I, knowing full well that I was crossing swords with an expert, would not cry defeat. Nor would the Duke: ‘You have a place in my household. I am your lover. You share my bed to our mutual enjoyment.’

How cold, how flat the statement of our relationship, yet there was fire in his eye. Assuring myself that we had no audience:

‘I am afraid,’ I announced baldly.

‘Afraid? Of what?’

‘Rejection.’

‘God’s Blood, Katherine!’

‘I see your affection for the Duchess growing stronger. I fear I am superfluous,’ I said. ‘I expect it is the penalty a mistress must pay if she is absent for the months of childbirth.’

‘What penalty? There is none, except of your own making. You have closed your door against me!’

‘And you defended the Duchess quite superbly,’ I retaliated. ‘I recall perfectly. She is your wife and mistress in the eye of God and Man.’

‘Ah, so that’s it! Constanza’s childish game-playing!’ His brows continued to express disbelief. ‘What would you have me do? Open you both to scandal through some malicious game?’

‘Of course not.’

‘Constanza is my wife.’

‘I know she is.’

‘She deserves my respect.’

‘I have always known that too,’ I said, withdrawing behind my bulwarks in the face of such obvious statements.

‘And I have always been honest about my marriage to Constanza. What do you want from me, Katherine?’

There was the direct attack I had expected. I thought about this. How difficult to explain, but I did so with all the self-possession I had held to in past days.

‘I share your bed, my lord. I have carried your child. I think I need to know that you still need me in your life, that I am not here as some passing pleasure when the mood takes you.’