She laughed, and the clerk laughed with her. “It’s fetching enough,” the clerk said, thoroughly thawed now. “But even the royal family will lose if they don’t wager on Lord Cameron’s horses.”

“He’s Mr. McBride’s brother-in-law you say? A lordship?”

“Lord Cameron married our Mr. McBride’s sister. Scots, the lot of them.” The clerk shook his head, as if to say Mr. McBride would be perfect in his eyes except for that one little flaw. “Mr. McBride lives in London much of the time, though he has a big house in Scotland—he’s grown such a large practice here. Wouldn’t be surprised if he didn’t become head of chambers soon.”

“He must live in a grand London house then,” Bertie said, at last getting to what she wanted to know.

The clerk had well warmed to her now. “He does. I’ve been once. Big house in Mayfair, near to Grosvenor Square. So many rooms, huge staircase—I had to describe the whole thing to my mum at least a dozen times.”

Bertie asked him a few more questions, but either the clerk didn’t remember the exact address or he had no intention of letting on what it was. But it was a start.

“I say,” the clerk said, stepping closer to Bertie. “I’m off home now. Maybe I can stand you a half in the pub at the end of the road?”

Bertie put on her warmest smile. “That’s kind of you, but I have to be getting home to me dad. He’s a right bear when he doesn’t get his supper on time, and he’s got the biggest fists, I have to tell you. Like that.” Bertie held up both hands, showing an exaggerated size of her father’s. “Nice chatting with you.”

The clerk looked suitably alarmed by thoughts of her violent father, even though he expressed disappointment. He tipped his hat, and the two of them parted.

It had been too late to rush across London that night and track down the house near Grosvenor Square—Bertie hadn’t been exaggerating about her father’s temper when he didn’t have his supper on time.

The next day, then, Bertie made her way to the heart of Mayfair, rambling along the roads that connected directly to Grosvenor Square. The square itself was bounded by four wide streets; in the center was a large stretch of green with trees, surrounded by a fence with a big gate. A nice little piece of countryside for those who lived on the square to enjoy.

Three days Bertie had come to the square and wandered the streets, looking for any sign of Mr. McBride. She was careful to pretend she was a slavey on an errand or out shopping, so no constable would arrest her as a girl on the game. She’d die of mortification if she were taken for a prostitute, and her dad would thrash her good before she had a chance to prove her innocence.

Apparently, she looked respectable enough, because the constables left her alone and no one along the busy streets complained about her. It was early on the third day of her investigation that she stood eating chestnuts and watched Mr. McBride emerge from his very tall, very elegant brick house on Upper Brook Street, which led from the west side of Grosvenor Square.

The ground floor’s large bricks were painted white, which made the black door with fanlight all that more sharp. The tall windows didn’t have arches over them, but they were regal, becoming smaller on each story as the house climbed—at least five floors that Bertie could see. Delicate wrought-iron railings ran across the windows of the first floor rooms, while the ground floor was encased in a more functional railing, with stairs that ran down to the scullery and kitchen.

While Bertie stood eyeing the house after Mr. McBride had ridden away, absently popping another chestnut into her mouth, the red-haired Scotsman, Macaulay, turned her way. His blue gaze bore into her so fiercely that Bertie almost swallowed the chestnut whole.

She quickly assumed a nonchalant look and hurried across the street and down toward Park Lane. Just a harmless young woman, she made herself convey, taking a day out to see the sights. She felt Macaulay watching her, but by the time she was brave enough to turn back, he was gone, the door of Mr. McBride’s house shut.

Bertie didn’t trust that the man wouldn’t be peering out the windows, so she turned her steps to Hyde Park, on the other side of Park Lane. A gate not far from Upper Brook Street led into the park, and Bertie kept up her rapid pace as she went through that gate, finishing off her chestnuts and crumpling the paper into her pocket.

Even in winter, Hyde Park was a vast expanse of lawn dotted with trees, a relief to eyes accustomed to jammed-together gray houses and teeming streets. Bertie liked to come up to the park when she had the time, to look at the flowers in summer, the trees turning colors in autumn, and the horses trotting along the Rotten Row any time of year. She liked Regent’s Park even better, with its avenues of flowers and sloping lawns, but she couldn’t get that far north very often. How splendid it must be to live in the big houses around here and have this park nearly outside the front door.

“Master Andrew!” A sharp voice cut through the winter air. “You come back here! At once!”

A small object burst past Bertie from behind her, a red hat flying from a little head to reveal hair the same color as Mr. McBride’s. The hat belonged to a boy in a handsome coat, knee breeches, white stockings, and sturdy boots. Bertie was nearly knocked off her feet by this missile, his small arms and legs pumping, but she sidestepped and spun in place, catching her balance and preventing a fall.

A woman in black panted after the boy. She was hampered by the heavy coat she wore, and a hat with a small veil was slipping over her ear.