It’s a book that has desperately searched for its own ending for two long years. But the story still isn’t finished.

Released this month to coincide with the second anniversary of the 2001 bioterror attacks, “The Anthrax Letters” by Leonard Cole is a self-described “medical detective story.” And while it can at times deliver all the drama of a modern-day thriller, the 240-page book also offers the most complete look available at the still-unsolved mystery of how and why 22 people became infected with anthrax between Oct. 4 and Nov. 21, 2001.

“Perhaps a half dozen letters containing a quantity of powder equivalent in volume to a handful of aspirin tablets paralyzed much of America,” Cole writes. It remains a complicated and puzzling tale that took federal investigators, the American media and an anxious public from Florida to New Jersey and from New York to Capitol Hill.

“The Anthrax Letters” seeks to untangle the web of events by giving a day-by-day, and sometimes minute-by-minute, account of that confusing time. Along the way, Cole speculates on who might have had the capacity to carry out such an attack and assesses how prepared America is today for another act of bioterrorism.

Cole, an adjunct professor of political science at Rutgers University and an expert on the intersection between politics and bioterrorism, has written six books, including “The Eleventh Plague: The Politics of Biological and Chemical Warfare.”

In writing and in person, Cole combines his medical expertise and analytic assessments with an understanding of how the attacks affected the victims and their families. His book is written as a tribute to the American public health system that fought the outbreak, the 12 victims who have recovered, the five who are still sick and the five who lost their lives.

“Very soon into this I realized I was writing something different from anything I’d ever written,” Cole said. “I was not just writing as I have in the past, from a policy interest or a reporter’s interest. … It became clear to me that this is a hell of a fascinating human story. The human characters, the personalities, the emotions they went through, I really got to talk about personal issues.”

The Hart Connection

Taking the attacks a victim at a time, “The Anthrax Letters” begins with Bob Stevens. A husband and father who worked as a photo editor at a the Sun, a Florida-based tabloid newspaper, Stevens was the first casualty of the mail attacks. Mixing medical and scientific jargon, Cole explains the complicated testing procedures and the history of anthrax use without forgetting about the tragedy Stevens, his family and his doctors went through.

“I hope that what I could do uniquely was not only to grapple with the monumental template of all that was happening in a coherent way, but also to convey the sense of humanity about all this. That we’re all in this together,” Cole said in an interview. “These are folks, many of whom could reflect our own behavior, our own lives, and we got lucky, many of us, that we never opened up an anthrax letter. That’s the only difference between them and us.”

One section of the book that might be especially chilling to those who lived and worked in Washington two years ago is Cole’s description of how anthrax spores infiltrated the Hart Senate Office Building and paralyzed Capitol Hill.

“An intern had opened the threat letter in the sixth-floor mail room of the Senator’s suite,” Cole writes. “Under the date, ‘09-11-01,’ the letter contained seven lines: YOU CAN NOT STOP US. WE HAVE THIS ANTHRAX. YOU DIE NOW. ARE YOU AFRAID? DEATH TO AMERICA. DEATH TO ISRAEL. ALLAH IS GREAT.”

It was an unnerving time for anyone on Capitol Hill. Twenty people had been exposed to anthrax, 6,000 people had undergone nasal swabs, and staffers and Members alike remained on edge for months.

Cole’s speculation on the possible culprits is perhaps the most intriguing aspect of the book. He explains the FBI’s rationale for the “domestic loner” theory but also makes a case for a possible overseas connection.

The chapter cites the many coincidences that suggest some link to the Sept. 11 terrorists. Among them are the fact that six of the Sept. 11 hijackers lived near the Sun newspaper building, the first building contaminated with anthrax; that other hijackers lived in New Jersey, where the letters were mailed; the coincidence that the wife of the editor of the Sun had rented apartments to two of the hijackers during the summer of 2001; and the speculation, in hindsight, by a Miami physician that the lesion he treated on a hijacker’s leg in June 2001 was cutaneous anthrax, a view supported by Johns Hopkins University physicians.

With the culprit or culprits still on the loose Cole presents a frightening possibility. He also maintains that despite steps taken to improve emergency preparedness for bioterrorism, America still has much to do.

“Bioterrorism is no longer theoretical,” Cole said. “There is better coordination now. We are much more attuned to what to expect. … Medical research is the key to minimizing the effectiveness of a bioterrorist.”

The Victims Speak

To mark the second anniversary of the attacks, Cole and his publisher held a news conference earlier this month to announce the release of “The Anthrax Letters.” The event brought together four of the survivors of inhalation anthrax as well as Dr. Larry Bush, who diagnosed the first anthrax case in Florida. It occurred two years to the day when Bob Stevens entered the hospital with anthrax already spreading throughout his body.

But unlike the memorial services and national observances for the Sept. 11 attacks in 2002 and 2003, the event was one of the few ceremonies that marked the anthrax attacks.

“Interestingly the anxiety levels of many people were far more acute because of their concerns about their own mail during the months of the anthrax. Many people were more concerned than you would have found concerned about an airplane crashing into their building. … Yet it seems their concern has dissipated over time whereas Sept. 11 is such an acute, singular, momentary event. … It created an impact on the mind that the anthrax letters don’t.”

And the anthrax survivors who attended Cole’s conference say one of of their biggest fears is that America will forget what happened during those fall days of 2001.

Norma Wallace, a postal worker in the Hamilton, N.J., facility infected with inhalation anthrax, spent 18 days in the hospital and had six gallons of fluid drained from her chest. She still has joint pain and fatigue, and she went through post-traumatic stress disorder after the attacks. She said she is grateful that Cole has brought the issue before the American public again.

Leroy Richmond, an inhalation anthrax survivor who worked at the U.S. postal processing center in Northeast Washington, still suffers from short-term memory loss and fatigue and is still under psychiatric care two years later.

“Somehow people overlook that if it happens again it will be on a larger scale,” Richmond said. “Reading this book we might be able to find some hope for change.”