Mr. Wildstein, the former director of interstate projects for the Port Authority, is now the wild card in the scandal surrounding Gov. Chris Christie and the revenge-fueled closings of lanes leading to the George Washington Bridge in September. Last week, his lawyer released a letter saying that “evidence exists” to show that the governor knew about the closings while they happened, contrary to what he had said at a marathon news conference. The lawyer also wrote that Mr. Wildstein himself had evidence to show that the governor spoke inaccurately about Mr. Wildstein, whose hiring he had authorized at the agency that runs the bridge.

Mr. Wildstein is in a position to know the back story of the lane closings: He took the order from a staff member in Mr. Christie’s office to create “traffic problems” near the bridge.

While it is unclear what his evidence is — his lawyer is not saying — Mr. Wildstein’s time as Wally Edge reveals much about how he approaches politics, and, former sources and staff members say, much about his motivations and strategy now. And it marked an important — and at times, mutually beneficial — moment in his relationship with Mr. Christie. Eventually, he would become a crucial person for the governor at the Port Authority of New York and New Jersey, and find himself in the middle of the scandal.

Bridget Anne Kelly, whom Mr. Christie fired after she was revealed to be the staff member who gave the order to create traffic problems, was one of Wally Edge’s best sources. Bill Stepien, the former campaign manager whom Mr. Christie sidelined after his name surfaced in emails disparaging the mayor of Fort Lee, was one of the young operatives whose career he nurtured.

The scandal, former sources and employees say, is the kind of story that Wally Edge lived for.

“He’d love every single bit of it, except for how it impacts staffers,” said one former employee, who did not want to be quoted by name because of conflicts with a current job.