Bo Zenga's Hollywood tale began like one of those implausibly bright MGM musicals: a plucky unknown from south Jersey moves to Tinseltown with dreams of becoming a big shot. Before you know it, he's selling film ideas to topflight Hollywood execs. "Pitching in the Big Leagues," the Writers Guild magazine gushed in July 1998, with a cover photo of Zenga standing, script in hand, on the mound at Dodger Stadium. (Get it?) But Zenga's Technicolor fantasy quickly became the stuff of film noir. Convinced that he'd been cheated out of a producer's credit and millions of dollars for work he did on the hit film "Scary Movie," Zenga sued the talent-management company that brought him in on the project, a firm headed at the time by Brad Grey, now chairman of Paramount. To help fight Zenga, Grey and his high-profile lawyer, Bert Fields, turned to the one man in Hollywood you could always count on to dig up dirt on your rivals: Anthony Pellicano, whose reputation as a thuggish gumshoe was only enhanced by his penchant for toting a baseball bat.

Hunting for embarrassing tidbits, the private eye contacted Zenga's friends, former business partners, an old girlfriend--and even hassled Zenga's mother, says Zenga's lawyer, Gregory Dovel. What Zenga learned only later was just how far Pellicano may have gone to get his information: according to a sweeping, 112-count federal indictment unsealed last month, Pellicano is at the center of a wide-ranging conspiracy to gather damning information about his clients' opponents through unauthorized police background checks and illegal wiretaps. Seventeen of those counts--15 percent--stemmed from the Zenga litigation. Pellicano, who is being held without bail, has pleaded not guilty to all charges. But Hollywood bigwigs who hired him--and there are many--are on edge. Meantime, Pellicano's alleged victims are keeping L.A. lawyers busy filing civil suits against the detective and his associates. Last week Zenga expanded a civil suit he's filed against Pellicano to include Grey, Fields and their law firms.

Zenga's story offers a glimpse at how Pellicano's clients benefited from the private eye's activities, and raises questions of what they knew and how they knew it. Grey, Fields and Fields's law firm have repeatedly denied sanctioning or knowing of any lawbreaking by Pellicano. Sources close to the investigation--who requested anonymity due to the sensitivity of the probe--say the Paramount chairman, who made two appearances before the grand jury more than two years ago, has been told several times by prosecutors he is only a witness in the investigation. Fields has said he is a "subject" of the investigation, but not a target. (While "subjects" of federal investigations are open to indictment, they are not the primary focus of an investigation.) "The biggest shoe left to drop is whether Bert Fields will be indicted," says Loyola Law School's Laurie Levenson. Prosecutors have kept mum, saying only that they expect to file a new, expanded indictment in April.

In his "Scary Movie" suit, filed the day the film opened in 2000, Zenga maintained that a manager at Brillstein-Grey Entertainment promised him that he and the firm would be equal producing partners on the project. Brillstein-Grey denied it ever made such a promise, and then told Zenga he would have to negotiate on his own with the studio that bought the project, Miramax's Dimension Films. In the end, "Scary Movie" was a hit, earning $157 million at the box office. Grey and his firm walked away with more than $7 million from the deal, according to Zenga's suit. Zenga's take: $150,000.

From the beginning, Fields tried to discredit Zenga by painting him as a liar. Pellicano helped bury Zenga in a blizzard of allegations about his own conduct, including accusations that he'd puffed up his résumé. As a result, Dovel instructed Zenga not to answer hundreds of questions at a subsequent deposition. That led the trial judge to bar Zenga from testifying in his own case. Zenga lost, and failed on appeal, too. His lawyer blames the private eye. "If Anthony Pellicano had not been in the case, Bo would have testified, and we would have won," Dovel says. "He was incredibly effective."

Pellicano made his appearance in this drama about seven months into the suit. Grey had first encountered Pellicano in the late 1980s when their offices were in the same building on Sunset Boulevard. Years later, Grey approached HBO about developing a Pellicano idea for a TV series brought to Grey by a prominent agent and a famous director. Whose idea was it to bring Pellicano into the Zenga matter? "As the Zenga case was moving to trial, Mr. Grey and his counsel ... decided to engage Mr. Pellicano, whom the law firm had recommended and hired in prior litigation," says a Grey spokeswoman, who added, "Mr. Grey did not know of, and never condoned, any illegal activity by Mr. Pellicano."

The first evidence of Pellicano's wrongdoing in the Zenga case, according to the Feds, came on Feb. 6, 2001. That day, a Los Angeles Police Department detective who was allegedly on the private eye's payroll began a series of illegal background checks on Zenga, his wife and five others. The background checks started the day after Grey had finished a contentious three-day deposition. Among the zingers: after Grey repeatedly denied having been told that Zenga and the firm would be producing partners, Zenga's lawyer confronted him with a 1998 e-mail from a Brillstein-Grey manager informing Grey that "BGE (Brillstein-Grey Entertainment) and Bo Zenga are producing this project for Dimension." "THANKS," Grey replied. Grey dismisses its significance: "Both the trial court and the Court of Appeals found the e-mail unpersuasive and threw out the case," says a Grey spokeswoman. Nonetheless, Zenga cited the incident in his amended civil complaint last week.

Within days of the deposition, Pellicano was allegedly tapping Zenga's phone, according to the federal indictment. Dovel says federal prosecutors gave him eight pages of typewritten wiretap summaries that they said Pellicano had written after listening in on Zenga's calls. "Some of it was word for word," says Dovel, who cited those notes in his filing last week.

Pellicano succeeded in creating what Dovel calls an atmosphere of "fear and uncertainty." He says Pellicano began paying visits to potential witnesses to dig up new dirt, and launched a campaign to win over Zenga's ailing mother, Madeline Thomas, who has since died. Then there was Pellicano's unsettling ability to tip off his bosses to details of Zenga's case. Once, Dovel and Zenga were talking over the phone about an account Zenga held at a bank that had been merged out of existence. "Bo is trying to get copies of his checks," Pellicano wrote in his summary, Zenga's suit claims. Within days, the successor bank received a call from Pellicano and a subpoena from Fields's firm. Dovel says the coincidences piled up to the point that he and Zenga wondered whether their phones were tapped--though at the time they dismissed the suspicion as "paranoia."

In 2003, Zenga was called to appear before the grand jury investigating Pellicano. That probe, which led to the current scandal, began after Pellicano allegedly arranged to have a dead fish and a sign reading stop placed on the broken windshield of a Los Angeles Times reporter who was working on a story about possible Mafia ties to actor Steven Seagal, a Pellicano client. The day before Zenga was set to testify, Dovel says, a man came to Zenga's door telling him that one of his car windows had been broken. After Zenga had a look, he went back in the house and the phone rang. A man at the other end said, "Don't." But Zenga went before the grand jury anyway. While Zenga's reputation in Hollywood was tarnished for a few years after the "Scary Movie" suit, his work on 2004's "Soul Plane," which he helped write and produce, got him back in the game. Meantime, Pellicano is behind bars, awaiting his day in court. Perhaps Zenga's film noir will have a Technicolor ending after all.