She picked up the shoebox containing the letters, walked over to one of the drums, and upended the box. Blue and cream-colored stationery cascaded into the fire, causing a momentary flare.

“No!” cried Lady Matheson.

“What’s the matter?” asked Mrs. Bainbridge, turning to her. “‘Burning them would be the best course of action.’ Those were your exact words, weren’t they?”

“Of course,” stammered Lady Matheson. “But—”

“Anything else would suggest that you still had ulterior motives for these letters,” continued Mrs. Bainbridge. “Such as using them to influence the selection of the princess’s future consort. Perhaps steering her away from Prince Philip so that some favourite of yours, or of one for whom you are working, might benefit.”

“I wouldn’t—”

“Or just to hold as a threat over her husband after the marriage. You do play the long game, Patience. Your name was well chosen. But this is all idle speculation on our part, isn’t it?” Mrs. Bainbridge walked over to her cousin, drawing herself up to her full height to look down at her.

“Isn’t it?” she asked again.

“Burning them was the proper thing to do,” said Lady Matheson, choking slightly on the words. “You saved me a match.”

“Then I think we’re done,” said Sparks brightly. “Thank you all for coming. Leave your masks with the lads outside.”

The Brigadier walked up to the edge of the firelight.

“Detective Superintendent,” he said.

Parham turned towards him. The Brigadier pulled out his wallet, removed a card, and showed it to him.

“Right,” said Parham. “She’s yours. But Stallings is mine.”

“That will be satisfactory,” said the Brigadier. “Take her to my car.”

His driver took Mrs. Fisher from the men holding her and led her away.

Parham turned to the spivs holding Stallings. “Now, would you two fellows mind taking my prisoner to my car?” asked Parham. “It’s parked a block away. I’ll meet you outside.”

“Look at us, assisting Scotland Yard in their enquiries,” muttered one of the spivs as they dragged Stallings towards the door. “I’ll never be able to look anyone in the face again.”

“Wait!” commanded Lady Matheson.

They stopped. She walked up and stood in front of them.

“Stallings?” she said.

“I’m sorry, Lady Matheson,” he said. “I never meant for it to—”

“The keys, Stallings. I need the keys for the Bentley.”

One of the spivs patted Stallings’s pockets, then reached into his coat and pulled them out. “Here you are, lady,” he said, handing them to her.

“Goodbye, Stallings,” she said.

She turned and walked back to Sparks and Mrs. Bainbridge, without watching as the spivs dragged him away. “What about the money?” she asked. “I assume, since it wasn’t exchanged for the letters, that you still have it.”

“Most of it,” said Mrs. Bainbridge, fetching the other shoebox from the table and opening it. It was filled with banknotes, with a neatly typed sheet of paper on top. “There were expenses,” she said. “The rental on this building for one night was surprisingly affordable.”