After hours of euthanizing monkeys, the group is exhausted, but none of the soldiers is willing to leave their post. One soldier, Specialist Rhonda Williams, develops a malfunction with her space suit and starts to lose air pressure. After an initial panic in the room, Williams is able to borrow a spare battery from one of the other soldiers. Still, Jerry Jaax decides to send her outside with Charlotte Godwin in order to take a break. During decontamination, Williams discovers that she has a hole in her suit.
Just as the two soldiers are leaving the building, a television news van pulls up. Gene Johnson orders both women to hide in one of the vans behind the facility. The television men wander around outside the building but do not see anything to pique their interest and soon leave. After exiting the van, Williams and Godwin go to relieve themselves in a nearby wooded area and discover a number of dirty hypodermic needles lying in the grass.
On the second day of the operation, Jerry Jaax and Sergeant Amen repeat their process of walking through each room of the facility to feed the monkeys and track the virus. After several hours of working in Room C, Jerry leaves for a short break, only to have a monkey escape its cage during his absence. The sergeants immediately exit the room, bar the door, and try to locate the animal by sight. Jerry decides that the safest option is to enter the room and try to capture the monkey with a net. He and Sergeant Amen are unable to catch the monkey and finally decide to leave the animal in the room overnight.
The other team members continue to euthanize the monkeys, which are growing increasingly agitated over the course of the day. Specialist Williams is first assigned to the euthanasia table, but Jerry later moves her to the bleed table to draw blood samples with Captain Haines. As Williams starts to take a blood sample from a monkey, she discovers that the animal is not fully unconscious. The monkey is about to bite Williams’s hand when another soldier injects it with a double dose of sedative.
Meanwhile, Peter Jahrling is working long hours in his laboratory in an effort to isolate the strain and determine how it is spreading. If he and Geisbert are able to isolate the strain before another laboratory, they will have the right to name it. While on a break, Jahrling checks in with Geisbert to see if either of them has started to develop symptoms of Ebola. Since they sniffed the contaminated flask, Jahrling has continually tested samples of their blood, but none of the samples have glowed under ultraviolet light. In a few days, they will both reach the end of the incubation period and know for sure whether or not they are infected.
On the third day of the operation, Nancy Jaax is awakened by a call from her brother, who tells her that their father is close to death. Nancy considers flying home to see her father but decides that she cannot leave her work in the middle of such an important outbreak. Her father dies later that day, while she is working in the hot area. By late afternoon, the team at the Reston facility has euthanized the last remaining monkey, including the monkey who escaped from Room C. While performing a final sweep of the building, Sergeant Klages discovers the freezer full with dead monkeys. Jerry orders him to leave the monkeys in the hallway for the decontamination team to destroy.
With the operation completed, the decontamination team scours the building with formaldehyde gas, effectively killing any remaining traces of the virus. Neither Peter Jahrling nor Tom Geisbert develops any symptoms, and Milton Frantig is diagnosed with nothing more than a bad flu and released from the hospital. Charged with finding the source of the virus, the C.D.C. identifies a monkey-storage facility in the Philippines as the starting point for the Reston infection. As in Virginia, however, none of the human workers at the facility exhibit symptoms of Ebola.
Almost a month after the Reston outbreak, the virus reappears at another monkey facility operated by Hazelton Research Products. The C.D.C. and USAMRIID decide to isolate the facility in order to observe the progress of the virus. The virus travels between rooms through the air ducts and effectively kills the entire monkey population. As before, there are no human casualties. Even an animal caretaker named John Coleus who cuts himself with a contaminated scalpel ends up showing no symptoms of the virus. The USAMRIID later discovers that all four caretakers at the original Reston facility test positive for Ebola Reston. However, the strain is symptomless in humans.
When Williams and Godwin discover the cache of dirty needles, Preston is alluding to the outbreaks of the Ebola virus in 1976 due to contaminated needles. While the needles found in the woods are not used for human injection, they serve as a reminder of the potential that human negligence can play in perpetuating disease. Even as USAMRIID believes the virus is contained in the Reston facility, it has already broken containment because the animal caretakers do not properly dispose of the syringes. Preston asks the readers to imagine the potential disaster if one of the children from the nearby center accidentally steps on an infected syringe.
In this section of the book, Preston strives to humanize the USAMRIID operation by focusing on the experiences of several new characters. Although the characters are given minimal backstory, Preston attempts to give the reader yet another perspective of a frightening situation. Rhonda Williams alone has three exposure scares, including a rip in her space suit, a malfunctioning battery, and a near-bite from an improperly sedated monkey. Throughout the experience, Williams remains wholly dedicated to her job and only leaves the facility to take a break at Jerry Jaax’s insistence. Williams’ commitment is shared by the other recruits in the operation who, despite being exhausted after hours of working, refuse to leave their posts. Even Nancy Jaax reveals her priorities by choosing to stay with the operation instead of visiting her dying father.
When Jahrling and Geisbert meet privately to discuss their symptoms, Preston juxtaposes their behavior with the selfless actions of the military personnel in the facility. While Williams immediately announces that she may have been exposed through a rip in her suit, Jahrling and Geisbert continue to keep their exposure a secret. Both scientists justify their decision by continuing to test samples of their blood, but their behavior is still ultimately self-serving. Williams faces the reality of the virus as she euthanizes hundreds of monkeys, and she recognizes what is at stake if she inadvertently takes the virus outside the hot zone. Jahrling and Geisbert, on the other hand, only see the virus from a detached perspective through slides and microscopes. As a result, they remain unaware, or perhaps unable to accept, the potential magnitude of their decision.
The outbreak at the second Hazelton facility gives the team an opportunity to observe the progression of the virus without any interference. While they had suspected that Ebola Reston is airborne during the first operation, they find definitive proof during the second outbreak as the virus travels from room to room through air ducts. The C.D.C. and USAMRIID also realize that the virus does infect humans but without causing any symptoms. While this discovery is positive for John Coleus, Milton Frantig, and the other animal caretakers, Preston notes the danger of an airborne virus that needs to undergo only a slight mutation before it gains the ability to destroy human tissue.
This second outbreak of Ebola Reston is also alarming because it is the direct result of a business decision made by Hazelton Research Products. Even though the C.D.C. traces the source of the Reston virus to a specific monkey house in the Philippines, Hazelton Research Products continues to purchase animals from the facility. This decision may be due to financial concerns or simple convenience, but either way, the company knowingly purchases additional monkeys from the same facility that caused the initial outbreak. It is fortunate that Ebola Reston remains harmless to humans through this second outbreak, or Hazelton Research Products would be solely responsible for any human deaths that occur.