Since David Coleman Headley was arrested more than a year and a half ago in Chicago, details of his terrorist secrets have trickled out including his connections to some of the world's most dangerous radical Islamists, top officials of Pakistan's military and intelligence service.
Even though Headley is now a U.S. government witness testifying against his accused accomplice, there are still some secrets.
As sirens squealed through the South Loop Wednesday night, a rush-hour street was blocked off so the government's most potent terrorist-turned-witness could be driven back to his federal safe house. Headley, in the back of a darkened SUV, had just finished day three of testifying against Rana, his boyhood friend. Federal Authorities say the two-man cabal ran Chicago's outpost of Lashkar-e-Taiba, according to Pakistan's most-feared terrorist organization known as LeT.
At least six years before Pakistani terrorists attacked its arch-enemy India and killed more than 160 people, Headley was personally groomed by the architect of the Mumbai massacre.
Headley's secret connection: Muzammil Bhat also know as three different aliases, a Lashkar-e-Taiba commander in charge of tactical training and pre-assault reconnaissance - both eventually were Headley's specialties.
It is unclear why Bhat has not been charged in either Chicago or India - even as Headley's other handlers have. Rana, who ran a Devon Avenue immigration and travel center, is on trial.
"I don't have to defend him...I know my husband. He is innocent. I love him," said Samraz Rana, Tahawwur Rana's wife.
Rana's wife says Headley is a liar.
"He has, like, I don't know, how many faces? The face I saw was not the one I saw in court today," said Samraz Rana in an exclusive interview with New Delhi TV reporter Sarah Jacob.
Headley frequently talked in a terrorist's code. Dr. Sahib is how Tawahhur Rana was referred to in emails; the game is afoot meant an attack was underway; a terrorist who got married actually got killed and new investment plans were really future terror plots.
Headley told investigators that the boys were code for a terrorist team; Rahul meant India; the Mickey Mouse project was a planned Denmark attack and checking out real estate was surveillance.
In some of Headley's surveillance, he posed as a tourist but was really scouting landmarks to attack.
The proposed terrorist attack in Denmark was aimed at a newspaper that published cartoons viewed as anti-Muslim. Arrests were made before the plot could be carried out.
On Thursday, Mr. Rana's attorneys will have a full day of trying to expose Headley's darkest secrets - his drug dealing, heroin use and criminal past, sometimes while working as a government informant.