Philo Vance [William Powell] is pulled into a tangled web of suspicion after Archer Coe [Robert Barrat] is found dead in his locked bedroom the morning after his defeat at the Long Island Kennel Club show, a loss that gnaws at Coe’s pride and prideful control over those around him. The show’s result leaves a sour taste in many mouths, and Coe’s death shocks everyone enough to prompt a quick, conventional conclusion: suicide. The pistol in his hand and the clean gunshot wound to the head seem to seal the matter, and District Attorney Markham [Robert McWade] along with Detective Heath [Eugene Pallette] are quick to close the case, treating it as a grim self-inflicted end. But Vance isn’t convinced that a man so controlling and vindictive would go to such lengths without leaving a thread to pull.
As Vance sifts the scene, he pieces together a crowded field of possible suspects, each with a motive tangled in respect, romance, money, and betrayal. Hilda Lake [Mary Astor], Coe’s niece, resents his tight grip on her finances and fears any man who draws near her; her courting flame, Sir Thomas MacDonald [Paul Cavanagh], suspects Coe of thwarting his chance to win both affection and a fortune. Raymond Wrede [Ralph Morgan], Coe’s devoted secretary, bears a secretly hopeful affection for Miss Lake, but his hopes were crushed when she chose another. Doris Delafield [Helen Vinson], Coe’s neighbor and briefly his lover, had been unfaithful, a fact that complicates matters further because Grassi [Jack La Rue], the man connected to a lucrative art sale Coe canceled, had financial leverage over her. The entrails of the household expose more players still: Liang [James Lee], the quiet cook who had labored long and hard to assemble Coe’s vast Chinese collection, learned too much and was dismissed when he overheard plans that could threaten Coe’s ambitions. Brisbane Coe [Frank Conroy], Coe’s brother, had always despised him for reasons unknown, and Gamble the Butler [Arthur Hohl] bore a shadowy criminal past that may still haunt the estate.
Brisbane’s alibi begins to fray when Vance discovers that his brother’s presence in the train era conflicts with the timing of the murder, casting doubt on the assumption of a straightforward suicide. Yet another clue surfaces: a copy of Unsolved Murders found among Brisbane’s possessions, its pages bookmarked to a method of locking a door from the inside using string and fishing tackle—an apparent hint that two men might have engineered the night’s events. Vance demonstrates the technique to Markham [Robert McWade] and Heath [Eugene Pallette], turning the page from an abstract idea into a tangible possibility: two minds, two hands, two plans, each moving toward the same deadly outcome.
The tension escalates as attempts on Sir Thomas MacDonald’s life follow the original murder, with the same dagger striking in his own bedroom. A Doberman belonging to Doris Delafield [Helen Vinson] is found grievously wounded in the Coe library, and a thwarted plan to stage a clean escape crystallizes: someone has a motive, an opportunity, and a willingness to commit murder in cold, calculated ways. An alibi from Raymond Wrede [Ralph Morgan] claiming he sought to end his employment with Coe on the night of the murder becomes a pivotal detail. Vance’s instincts sharpen as he begins to see the pattern: the killer is one of two men who intended to end Coe’s life, and the night’s chaos was a grim cover for a more elaborate plot than anyone anticipated.
With each new reveal, Vance narrows the field, guiding Markham and Heath toward a confrontation that will force the truth into the light. He orchestrates a tense encounter at the Coe residence, pitting Sir Thomas against Wrede in a staged quarrel over Hilda Lake, hoping to provoke a reaction that would expose the killer. The plan works in a dangerous way: the moment Sir Thomas and Wrede clash, the Doberman lunges, the tension peaks, and the realization strikes that the original killing wasn’t the end of the danger. In the heat of the moment, Wrede confesses that Coe struck him after he refused to help in his pursuit of Miss Lake, a confrontation that precipitated the violent struggle and the fatal stabbing. Yet Wrede refuses to let Brisbane’s murder lie as a mere accident, insisting that the deed would have been different if circumstances had allowed, and he adds a chilling caveat: if given the chance, he would still kill Sir Thomas.
Throughout this meticulous unraveling, Vance’s careful logic and the dogs, secrets, and loyalties of the Coe household coalesce into a troubling, but clear, portrait of motive and opportunity. The mystery pivots on revenge, control, and the selfish calculations of love and ambition, showing that the murder of Archer Coe was not the work of a single hand but a complex calculus shared by more than one person. In the end, Vance’s relentless pursuit of truth exposes the human pieces that fit together in a dangerous, political puzzle: a web of relationships fraying under pressure, a night where two would-be killers moved in the shadows, and a final revelation that the forces behind the crime were not as simple as a suicide, but far more intricate, with the dog’s innocence and the servant’s past mingling with the ambitions of the living to reveal the real truth behind the crime.
