Tom Lawrence, Tom Conway, the resourceful Falcon, slips into a dimly lit gallery late at night to retrieve a painting for Dolores Ybarra, Cecilia Callejo. There he uncovers a startling truth: the model for the artist’s work is Dolores herself, but the painter, Humphrey Wade, has been dead for fifteen years. The moment is further unsettled by the murder of the gallery’s owner, and when alarm bells trigger a security response, Tom fights his way free with the painting. He turns up at the doorstep of Winthrop “Lucky Diamond” Hughes, Emory Parnell, a noted collector of Wade’s canvases, and realizes his trouble is just beginning.
The trail soon carries Tom beyond the border into Mexico City, drawing Barbara Wade, the late artist’s daughter, into the middle of a dangerous mystery. At the airport, Barbara is whisked away by a car from La Casa Del Lago Inn, and she manages to slip free. Tom, ever vigilant, hires a taxi to shadow her, enlisting Manuel Romero, Nestor Paiva, and his son Pancho, Fernando Alvarado, for help. The destination is clear: a secluded inn in the countryside where Wade once worked, a place where secrets flutter as easily as shadows in the night.
Inside La Casa Del Lago Inn, Barbara is introduced to her stepmother Raquel, Mona Maris, a dancer with her own insider’s circle, and to Raquel’s partner and new husband Anton, Joseph Vitale, who warns Tom to steer clear of Barbara. The inn’s desk clerk Paula Dudley, Mary Currier, guides Tom to Wade’s studio, where a drawing done in Wade’s unmistakable style lies with wet paint still drying. Dolores Ybarra, Cecilia Callejo, searches for her own portrait, unexpectedly colliding with Tom in the corridor. When Tom returns to his room, an unseen assailant knocks him unconscious and makes off with the painting, leaving a thorny puzzle in his wake.
Amid the mounting tension, Don Carlos Ybarra, Pedro de Cordoba, presses for his missing daughter, only to learn Barbara’s body has turned up in a lake, prompting Tom to fear a murder most foul is connected to the Wade affair. Back at dinner, Barbara collapses—poisoned—deepening the intrigue and raising the question of whether Humphrey Wade might still be alive, an elusive figure whose survival could tilt the entire investigation toward profit and danger. If Wade is indeed alive, who benefits from keeping that truth under wraps?
The plot thickens as the island where Wade’s grave is said to lie becomes a focal point. They find Barbara heading toward the crypt, but the tomb is empty when Tom peels back the headstone. A woman attempting to slip away from the scene is revealed to be merely an accomplice with no knowledge beyond a paid assignment to lead Barbara to the crypt. After a ceremonial Danza de los Viejitos (Dance of the Little Old Men) performance, a man in an old-man mask steps forward and, to Barbara’s shock, reveals himself to be her father. Humphrey Wade explains that his supposed suicide fed the value of his paintings and allowed him to disappear, living off the mystery he created.
With Wade’s warning echoing in the air, he is suddenly shot dead just as Hughes—convinced Wade’s notoriety will ruin his own scheme—tries to strike. Tom pieces together that the killer is Hughes, and he stages a tense confrontation in the plaza, wearing Wade’s disguise to draw him out. Manuel shoots Hughes from a balcony, bringing the killer to justice. In the aftermath, Manuel presents Tom with a dark, engraved leather case, calling it a ‘memorandum’ rather than a memento—a subtle nod to the case’s intended purpose and the trust placed in Tom by his new allies. Pancho’s offer to buy the memo allows Tom to depart with gratitude, as he bids farewell to his Mexican friends and heads for home, boarding a plane with the shared sense that justice has prevailed and adventure has found its quiet ending.
