It was a pleasure having done business with you. Wish you luck for your future. Dr. Akhil Bansal.

CENTER CITY

Akhil wasn't the only one struggling with finances.

On a frosty morning, James Pavlock, a money-laundering expert up from Washington, settled into a temporary office on Chestnut Street, half a block from Independence Hall. He knew the city well, having once served as a Philadelphia assistant district attorney, and he kept a home here.

Among his first visitors was Aaron Carp, the eager, 25-year-old IRS agent. Carp opened a thin file - spreadsheets of Akhil's bank records.

The numbers, grouped by account, showed tens of thousands of dollars moving every few days. It was good work, Pavlock told Carp, but just a beginning. There was no pattern. Or apparent motive, or hard evidence of a crime.

Carp was stumped. What should he do?

Pavlock lived for such moments - an agent who wanted to talk spreadsheets. They spoke for two hours.

"OK, now what?" Carp said.

They would subpoena U.S. banks and begin using diplomatic channels to seek foreign bank records. This meant getting cooperation from as many 10 countries. That might take months.

Pavlock didn't have months. Given the public-health threat - addictive pills sold willy-nilly to anyone with a credit card - prosecutors wanted a speedy indictment, maybe by late March.

Finding the money was vital: First, bank records would help prove that the Bansals were drug dealers on a wide scale. Second, the records could prove money-laundering, a charge that would increase any prison sentence. Third, money found could be seized, stripping the Bansals of all profits. Fourth, and not least, agencies seizing the money - millions - would get to keep it.

ROXBOROUGH

Akhil scanned his latest e-mail and fumed.

It came from his best client, Corrina Meherer in Costa Rica.

"There is a leak within your organization," she warned.

She was getting spam, she explained, from a new Web site, one that shipped pills from a familiar address in Queens, N.Y. - 5028 Utopia Parkway.

David Armstrong's house!

Armstrong was a thief! Akhil's shipper was stealing his pills, selling them through his own Web site.