The minute he touched it, he knew. Or that’s what he said afterwards, when he described the cold shiver. This didn’t grow in any farmer’s field.

Chapter One

No matter how many times I come to London, I still love to look about me, even if it is only at the shops and the risk-taking pedestrians on Gray’s Inn Road. Young DC Martin Yeats left me to my gazing, which I curtailed a little so as not to be classed as a country bumpkin. The driver wove in and out of the traffic until we drew up at the grand granite-faced building on the Embankment that is New Scotland Yard.

Once inside, we exchanged the smoke of the city for a fug of cigarette fumes, mingled with fried bacon. Someone must have been sent to bring sandwiches.

As befits a man of high rank, Commander Woodhead had his office on the top floor, reached by a juddering lift. I first met him and his wife when Mother and I were staying in London with Aunt Berta. As young men, he and Uncle played in the same rugger team. I remembered him as tall and broad, with a shock of dark hair.

The man who stood as I entered his office was slightly stooped. His hair, though still plentiful, had turned white. He looked ancient beside the young detective constable.

As my father often said, the war robbed institutions of a middle generation. Now old and young worked side by side, looking at each other across a sometimes incomprehensible divide. That absence of the men in the middle benefited youngsters like Martin Yeats. He surely must be entrusted with greater tasks than escorting a lady detective from King’s Cross.

The commander came round to my side of the desk to shake hands. “You’ll have had refreshments on the train, Mrs. Shackleton?”

If that was his polite way of telling me not to waste his time over tea and buns, it worked. “Yes, thank you.”

He took a seat and motioned to DC Yeats to draw up a chair. In spite of his haste in wishing to jump to the business in hand, he observed the usual courtesies, asking about my mother and aunt.

He had probably seen my aunt more recently than I had, but the less said of that the better.

It did not take long for him to meander almost to the point. “How much do you know, Mrs. Shackleton?”

“Only that you wish to talk to me about a special assignment, connected with a crime thought to have been committed in the West Riding.”

He nodded. “That is so.”

I waited. If this was a game of drip-dripping information, two could play. Let him start. He began by telling me something that I already knew.

“The LNER runs a special express train from Ardsley to London during the forced rhubarb season. It carries up to two hundred tons of rhubarb to supply the London markets.”

I knew about that train, timed to arrive in London before dawn, daily between Christmas and Easter. It doesn’t always do to begin by correcting a person who ought to be well informed, but that did not stop me. “The starting point is Leeds Central Station, Mr. Woodhead.” Ardsley was the major junction for the surrounding areas.