Snake Eyes

Set during one long night, corrupt, flamboyant Atlantic City police detective Rick Santoro (Nicolas Cage) attends a boxing match at Gilbert Powell's (John Heard) Atlantic City Arena between heavyweight champion Lincoln Tyler (Stan Shaw) and challenger Jose Pacifico Ruiz. He meets up with his best friend since childhood, Kevin Dunne (Gary Sinise), who is a US Navy Commander working with the Department of Defense to escort Defense Secretary Charles Kirkland (Joel Fabiani) and Powell at the fight after a trip to Norfolk, Virginia. As the first round begins, Dunne is distracted by an attractive redhead named Serena (Jayne Heitmeyer) who wears a ruby ring, and leaves his seat, which is then taken by Julia Costello (Carla Gugino), a mysterious woman with silver-lined eyeglasses, platinum blonde hair and a white satin suit.When Tyler is unexpectedly knocked out by Ruiz, gunshots ring out, mortally wounding Kirkland and grazing Julia Costello's left arm, who loses her glasses and blonde wig, revealing her naturally dark hair. Dunne kills the sniper, and Santoro orders the arena to be locked down. Despite the lock down, Costello escapes into the casino, covers her wounds in pieces of cloth from her blouse and after stealing a blue satin jacket, disguises herself as a hooker.Santoro becomes suspicious when he notices that the "knocked out" Tyler woke up instantly when the shots rang out, and after studying the fight tape, realizes the knockout punch didn't connect. Tyler confesses that he threw the fight in order to pay gambling debts, but he was never told that anyone would be killed, and reveals that he was paid to take a dive by Serena, the same woman in red who tricked Dunne into leaving his post.With the involvement of Tyler, Serena and the sniper - in addition to the man who signaled Tyler to go down and whoever gave him the go-ahead - Santoro suspects a conspiracy and reveals everything he has learned to Dunne. Dunne confesses that the trip to Norfolk was for a test of the AirGuard missile defense system, which Powell's company was backing. He deduces that the sniper, a known Palestinian terrorist named Tariq Rabat, learned of the test and assassinated Kirkland in order to stop the sale of the system to the US government.Santoro goes to study surveillance videos from the security room in order to find Serena while, with the help of Powell's security guards, Dunne continues his search for Costello but, once they split up, it is revealed that Dunne is actually the fifth party and mastermind of the conspiracy. He kills the now-blonde Serena and Zietzthe man who signaled Tyler to go downin order to prevent their further involvement, with the help of his bodyguards. Dunne then enlists Tyler by revealing the truth to him.Meanwhile, Costello seduces Ned Campbell (David Anthony Higgins), a sleazy guest at the hotel, so she can hide in his room. Both Santoro and Dunne discover this at the same time and give chase, but Santoro reaches her first and takes her into protective custody. She confesses that she is an analyst who worked on the AirGuard tests and discovered that the results of the tests were faked; the system failed to work and she tipped off Kirkland to the deception. However, Dunne learned of her actions and arranged the entire conspiracy to kill both her and Kirkland. Santoro learns of Dunne's involvement and, despite his initial refusal to believe it, quickly realizes that his childhood friend is indeed the mastermind.After hiding Costello in a warehouse, Santoro inspects the footage of a new floating camera, and discovers proof of Dunne's involvement. Dunne confronts Santoro and confesses that his motive is to prevent any further attacks on US ships, similar to the one where he had to witness several soldiers drown, then offers Santoro one million dollars for Costello's location, where she will be killed, and Santoro would look the other way on the plan. When Santoro refuses, Dunne has Tyler beat him up, but he still does not give in. Dunne plants a tracker on Santoro and follows him to the warehouse just as Hurricane Jezebel strikes the Atlantic City coastline. When a tidal wave hits the boardwalk, Santoro uses it as cover to rush Costello outside, where the police, tipped off by Santoro, are waiting and witness Dunne opening fire. When captured by the police, Dunne, realizing his plan has failed, fatally shoots himself.Santoro is later hailed as a hero by the mayor of Atlantic City, but the press soon uncovers his corruption and he loses his job, his wife, his lover and custody of his son, along with his dream of becoming the next mayor of Atlantic City. He is arrested, convicted and sentenced to prison. Before reporting for his prison term, Santoro meets Costello on the boardwalk. She thanks him for his help, as Powell is completely restructuring his company and scrapping the AirGuard, saving the lives of many soldiers. They kiss, and Santoro promises to call her when his sentence is up in twelve to 18 months. After she leaves, Santoro muses that he at least got to be on television.Ultimately in the final shot, Serena's ruby ring is seen embedded in one of the concrete pillars of the new Powell Millennium Arena, revealing it as her final resting place.

Question: What does the final shot reveal about Serena's ruby ring?
Answer: It is buried in a pillar of the new arena.