In the city that swallowed up Daniel Pearl, a sense of menace still hangs as heavy as the sultry air.
A high-profile new film has focused renewed attention on the case of the Wall Street Journal reporter who was kidnapped and executed by Islamic insurgents here in 2002, and has underscored the fact that many questions remain unanswered.
Investigators in this teeming port city, a longtime hub for Islamic extremists, acknowledge that not all those responsible for Pearl's killing have been brought to justice. And many analysts believe that though the case remains open, the full story behind the kidnapping plot probably will never be known.
"We're never going to get the whole picture," said Christine Fair, a senior research associate in South Asia and terrorism at the U.S. Institute of Peace in Washington. "It's like a quilt -- it leads you to another patch, and another."
The most persistently nebulous element of the case, analysts say, is how much Pakistan's powerful Inter-Services Intelligence agency knew about the events surrounding Pearl's capture and execution. Pakistani military intelligence has a history of entanglement with the Islamic militants it is charged with policing.
"There are officials within the security services who are not entirely interested in seeing this [investigation] go forward," said John Harrison, a senior researcher for the International Center for Political Violence and Terrorism Research in Singapore. "Not that they were involved in the murder itself, but there are definitely embarrassing connections between the ISI and many of the perpetrators."
These dark and various complexities underpin the film "A Mighty Heart," starring Angelina Jolie and produced by Brad Pitt, which opens in U.S. theaters Friday. Karachi is the real-life backdrop of the events depicted in the movie -- which is based on a book by Pearl's widow, Mariane -- though much of the filming was done in India.
The narrative traces the harrowing days and nights that followed the journalist's disappearance, the desperate hunt for clues and the shattering denouement: Mariane Pearl, then six months pregnant, learning that her husband had been beheaded by his captors.
'So much that is hidden'
Five years on, the web that ensnared the 38-year-old reporter has tendrils everywhere in Karachi, whose 15-million-plus population makes it one of the world's megacities, a dizzying mix of festering slum and chic high life.
Home to a network of shadowy extremist groups and a virulent criminal underworld, the city is beset by rising religious militancy, simmering ethnic hatreds and frequent outbreaks of political violence. Karachi's sheer size at times renders it nearly ungovernable, authorities acknowledge.
"With everything that converges here, we have insufficient police resources," said Sain Mirani, acting director-general of the operations branch of the Karachi police. "There is so much that is hidden, clandestine, and we are always lagging."
Four men have been convicted in connection with the Pearl case. But the Pakistani legal system is a convoluted one, and appeals have been pending in the courts for years, and could take years more to move forward.
The most prominent of the four defendants was British-born Ahmed Omar Saeed Sheikh, sentenced to death in July 2002 for helping lure Pearl to the fateful meeting. But he is seeking to have his conviction overturned on the basis of a reported confession by Khalid Shaikh Mohammed, the alleged No. 3 in Al Qaeda, who is said to have claimed to have personally beheaded the journalist.
Karachi has for years been a crossroads for Islamic militants. The city's deepwater harbor on the Arabian Sea is a prime engine of Pakistan's economy, but the chaotically busy port also serves as a transit point for weaponry and Islamic militants bound for the fight against U.S. and NATO-led forces in Afghanistan, authorities say.
U.S. and Pakistani investigators say that there is a continuing overlap between homegrown Pakistani militant groups and broader-based international organizations such as Al Qaeda, and that Karachi has been used as a sanctuary and staging ground.
Karachi was a frequent pit stop for Mohammed, who was arrested in 2003 in Rawalpindi, near Islamabad, the Pakistani capital. But some investigators regard his reported claim to have been Pearl's executioner as possibly tainted by his penchant for exaggeration.
"It'll be debated for a long time," said one FBI agent.
American officials consider Karachi so dangerous that the U.S. Consulate is an armed fortress whose skeleton staff lives and works in a state of virtual lockdown.
The consulate, surrounded by barbed wire and blast barriers, has been the target of repeated attacks, including a truck bomb in 2002 that killed 12 people and a suicide car bombing in March 2006 that killed four, including an American diplomat.
But like any enormous metropolis, Karachi contains a multitude of worlds. It is Pakistan's commercial capital, as well as a vibrant arts and cultural center. Karachi natives tend to have a fierce pride in their hometown, insisting that the lively, eclectic rhythms of daily life give the lie to the city's dangerous reputation.
At a recent late-night cocktail party in a wealthy but bohemian district, not far from the rented villa where Daniel and Mariane Pearl stayed while he was working in Karachi, the guests included an up-and-coming fashion designer and an elegantly coiffed television personality. They sipped icy peach-vodka concoctions from tulip glasses while exchanging the latest political and literary gossip.
"Everyone in the outside world thinks of Karachi as some kind of crazy 'Terror Central,' but it's a regular place, a place where people go about their lives," one party guest said.
Although the Pearl case has been marked by long periods of inactivity, recent weeks have seen a small but potentially significant flurry of developments. But some raise as many questions as they answer.
Early this month, Pakistani police announced the arrests of two more men suspected of involvement in Pearl's abduction and killing. The pair, identified as members of a Pakistani militant group, were picked up in a remote area of Sindh province, of which Karachi is the capital, with a small arsenal of weapons.
And in April, a Pakistani man who owned the property where Pearl was held and had dropped out of sight soon after the kidnapping, finally surfaced -- but emaciated and on the brink of death. The family of Saud Memon said he was dumped outside his home and died weeks later in a hospital.
The family said through lawyers that it believed Memon had been in the custody of Pakistani intelligence at some point, and that it was trying to determine whether he also had been held at the U.S. prison at Guantanamo Bay, Cuba.
Other evidence in the case is vanishing.
The concrete shed where Pearl was held, together with the nearby shallow grave where his dismembered body was unearthed months later, was surrounded at the time by remote scrubland and a slum district inhabited mainly by Afghan refugees -- the kind of lonely location where kidnappers could avoid unwanted attention.
But as the city pushes outward, the area is today being overtaken by frantic development. A Hyundai dealership has sprung up on the roadside. Billboard advertisements announce the coming of high-rise apartments and shopping malls.
Lisa Curtis, a senior South Asia research fellow at the Heritage Foundation think tank in Washington and a former CIA analyst, believes there are larger long-term lessons to be learned from the case.
"The Pearl kidnap and murder was a sophisticated operation, involving both Al Qaeda and local Pakistani groups," she said. "To me, it demonstrates the pitfall of Pakistan not cracking down on all violent extremist groups, of seeking an accommodation with some -- that was a futile policy."