“Maybe. There are three more for Private MacDuggal. One for a Corporal Frederick Smith, one for a Lieutenant E. Shields, and two here for a Nora Cooper.” He passed them to Lia.

Return to Sender, Not at This Address had been scrawled next to Nora’s name.

“Nothing to an Estelle Allard, is there? Something that might prove she was here? Or stayed here and made your grandfather think he imagined an angel?”

“Doesn’t look like it.”

Lia hadn’t really expected a different answer. “I wonder why these were never put back in the post.”

“Put aside and forgotten? Stuck in a to-do pile that never got done?” Gabriel murmured as he continued to examine the rest of the stack in his hand. “Who knows?”

Lia set the letters she held aside.

“Here’s one to Sophie,” Gabriel said. “The wrong Sophie, but a Sophie nonetheless.” He held up a letter with a disappointed sigh.

It was larger than a regular airmail envelope, the stamps postmarked with smudged ink. SOPHIE KOWALSKI, followed by Millbrook’s address, had been typed in neat rows across the front. Return to Sender, Not at This Address had been likewise written across the front in the now-familiar hand.

Lia reached for the envelope, and Gabriel handed it to her. It was thicker than the other letters and had a more official bearing. The left top corner was creased, something small yet bulky preventing it from lying flat. She turned it over. INTER-SERVICES RESEARCH BUREAU with a London address was stamped on the back of the envelope, the seal brittle with age and broken in some places. She stared at the top line before flipping it back to examine the postmark. The smudging made it hard to read the month and day but the year was clear. 1943.

“This might not be the wrong Sophie,” Lia said slowly.

“What?” Gabriel had stood and had begun collecting the folders stacked around them.

“This letter is from the Inter-Services Research Bureau. Otherwise known as the Special Operations Executive.”

“Special agents.”

“Special agents, spies, saboteurs. Many who operated in France.”

Gabriel dropped back to his knees beside Lia. “You think that this Sophie Kowalski was actually my aunt?”

“It’s possible, I suppose.” Lia held the envelope gently in her fingers. “The date on the postmark fits the photos we found. And the first name fits, even if the last name doesn’t. Maybe Kowalski was another code name. Like Beaufort.”

“I don’t know.” Gabriel didn’t sound convinced.

“Your grandfather would have searched for Sophie Seymour. Not Sophie Beaufort or Sophie Kowalski. Maybe that’s why he never found anything. Maybe his answers are in here.”

“Maybe.”

“There is one way to find out,” she said, holding out the envelope. “Open it.”

“And if it’s not the right Sophie?”

“Then we will do our best to get this to whatever family Sophie Kowalski might still have left with whatever information we find. Either way, we need to know what is in the letter.”