Murder on Charing Cross Road — Joan Smith

The Berkeley Brigade -- Lord Luten, Corinne deCoventry (newly Lady Luten), Sir Reginald Prance and Coffen Pattle -- soon have a chance to aid their country by bringing a spy to justice. Their one clue, written by the victim in his blood, to the spy's identity is baffling. But the spy seems to know every move they make -- and to foil them while taking advantage of their difficulties. 9th Berkeley Brigade Mystery. Regency Mystery by Joan Smith; originally published by Belgrave House/Regency Reads