The Diamond Trap is the story of a New York City cop (Detective Rollings) and his partner (Brendan). Detective Rollings, a cop on the verge of retirement and in the waiting for a big case, finds himself involved in a cleverly planned heist of $12.5 million in jewels, after he and Brendan apprehend a male hooker attempting to sell stolen goods to a jewelry store owner (Rosencrantz).
In an effort to save himself, the male hooker is forced to tell the two cops about the planned robbery of diamonds at the Heritage Gallery. Investigating this story, the two cops are led to a beautiful young woman (Tara Holden) who works at the gallery, and she begins to show signs of nervousness when being questioned about the planned heist, thus convincing Detective Rollings that she is involved in the crime.
Consequently, Tara Holden gives herself up, and has no choice but to help the two cops catch the thieves. But their hot leads turn into dead ends through the double deceptions of their beautiful accomplice. Entangled in treachery and intrigue, their ambition to nail the gang turns into an obsession, as they are led into a crazy maze of deceit from New York to London.