As the Special Investigator to the Lord Chancellor's Visitor in Lunacy, Sebastian Becker delivers justice to those dangerous madmen whose fortunes might otherwise place them above the law. But in William James he faces a different challenge; to prove a man sane, so that he may hang. Did the reluctant showman really burn down a crowded pavilion with the audience inside? And if not, why is this British sideshow cowboy so determined to shoulder the blame?

The Authentic William James is the third novel to feature ex-police detective and former Pinkerton Man Sebastian Becker, joining The Kingdom of Bones and The Bedlam Detective. Praising "this superbly crafted thriller", Kirkus Reviews named The Bedlam Detective one of their 100 Best of the Year and called it "that rare beast, a literary page turner". MysteryTribune described it as "a rare literary masterpiece for lovers of historical crime fiction."

"It's a blinding novel… Each chapter had me chuckling with joy—if not at the acerbic wit, the brilliant dialogue—the sheer spot-on elegance of the writing: the plot turns, the pin sharp beats. Always authoritative and convincing, never showy. Magnificently realised characters in a living breathing world… Absolutely stunning"—Stephen Volk, author and screenwriter (Ghostwatch, Afterlife, Gothic, The Parts we Play)

"British author Gallagher gives Sebastian Becker another puzzle worthy of his quirky sleuth's acumen in his outstanding third pre-WWI mystery (after 2012's The Bedlam Detective ). As the special investigator to the Lord Chancellor's Visitor in Lunacy, Becker is charged with investigating "the psychology of anyone with a fortune or an income that might be put at risk by their erratic behavior." When a fatal arson at a Sussex theater claims the life of a German prince, Becker's superior is eager for him to demolish any claim that the prime suspect, showman William James, was insane when he set the fire. After meeting James, Becker is prepared to give some credence to the man's claims of innocence. That comes back to haunt him when James manipulates him into facilitating his escape, leading the detective on a search for the fugitive—and the truth—that takes him to Pennsylvania and an apparent dead end. Gallagher makes the most of his unusual concept in the service of a twisty but logical plot line."—Publishers Weekly Starred Review