They’d walked up Berkeley Street, and around the square, then down Bolton Street. They were presently walking up Clarges Street. Reaching the corner where it intersected with the mews, they turned left toward Queen Street. Ahead of them, a black carriage slowly rolled across the end of the mews, going up Queen Street.
 
 Penelope frowned. “I could have sworn I saw that carriage before.”
 
 Barnaby grunted.
 
 Penelope didn’t say more. The carriage was a small black town carriage, the sort every major household had sitting in their stables, their second carriage. Why it had stuck in her head—why she was so convinced she’d seen that particular carriage earlier…she remembered where. They’d been crossing the northwest corner of Berkeley Square when the carriage had cut across Mount Street a block ahead of them, trundling in that same slow manner up Carlos Place.
 
 She’d turned her head and looked at it; the angle of her view of the horse, carriage, and coachman on the box had been exactly the same as it had been a few minutes ago.
 
 But why such a sight—to her, in this area, such a common sight—should so nag at her, why the certainty that it was the same carriage should be so insistently fixed in her brain, she had no clue. She puzzled over it as they walked quietly along, carefully scanning shadows, glancing down area steps, but came to no conclusion.
 
 Reaching Queen Street, they hesitated, then Barnaby tugged her to the left. Settling her hand more comfortably in his arm, she strolled beside him. In another season, anyone seeing them would have thought them an affianced couple taking a long stroll the better to spend time in each other’s company. With winter in the air, such a reason was unlikely, but their slow, ambling progress gave them plenty of time to examine the houses they passed.
 
 Just like the couple she saw walking along the other side of Curzon Street.
 
 Reaching the corner where Queen met Curzon, she stared, then tugged on Barnaby’s arm. When he glanced her way, she pointed across and down Curzon Street.
 
 He looked, then snorted.
 
 In unspoken accord, they crossed to the southern side of the street and waited until the other couple strolled up.
 
 Stokes looked shamefaced. He shrugged. “We couldn’t think of anything else to do.”
 
 “Hostages or not, we couldn’t sit at home and do nothing at all,” Griselda stated.
 
 “Anyway,” Stokes said, “I take it from your presence here you felt the same.”
 
 “Actually”—Barnaby glanced at Penelope—“our presence here is more a response to direct action.”
 
 Stokes was instantly alert. “What happened?”
 
 Barnaby described the “diversion.”
 
 “We sent a message,” Penelope said, “but if you’ve been out walking, they wouldn’t know where to find you.”
 
 Stokes nodded. “But we’re here now—and you’re right. Theymustbe doing more houses tonight.” He glanced around. “And most likely in this area.”
 
 “Given the diversion was in Jermyn Streeet,” Barnaby said, “which beats in Mayfair are most likely to be currently deserted?”
 
 Stokes saw his point. He waved to the south. “If we take Piccadilly as the southern boundary, then all the way to the Circus, then up Regent Street”—he pointed to the east—“up as far as Conduit Street. From there, across Bond Street to Bruton Street, along the top of Berkeley Square…and as your rooms are at this end of Jermyn Street, then they’ve probably come running from as far north as Hill Street, and probably”—he turned to look back along Curzon Street—“from all the areas out to Park Lane.”
 
 “So we’re standing more or less in the middle of the deserted patch?” Penelope asked.
 
 Jaw firming, Stokes nodded. “Depending on where in the beat they were, but I haven’t seen any constables since we headed this way.”
 
 “We haven’t seen any, either,” Barnaby said, looking around, “but then we started from where they’ve all gone.”
 
 Stokes swore beneath his breath. “Let’s divide the area and split up.”
 
 He and Barnaby put their heads together and sorted out routes. Stokes nodded. “We’ll meet up again on the south side of Berkeley Square, unless either of us sights the beggars. You’ve got your whistle?”
 
 Penelope patted her pocket. “I have it.”
 
 Barnaby retook her hand. He nodded a farewell to Griselda, then met Stokes’s eyes. “If either of us see a bobby, or even a hackney, we should send word to the Yard and get them to send more men this way.”
 
 Stokes saluted and reached for Griselda’s arm.
 
 Barnaby and Penelope turned to head east along Curzon Street. Before they’d taken even one step a shrill shriek cut through the night and froze them.