ReGenesis

Lilith befriends Mick, who is dying and desperate for David to help him discover if he really is a clone and possibly save his life. Meanwhile, NorBAC has managed to locate patient zero and must proceed with the interrogations at "Hazmat City." Was this an act of Bioterrism? Caroline is determined to find out whos responsible as more die and one more is exposed. David must now face his fate.

NorBAC investigates an outbreak of prion disease (mad cow) in humans. The victims are spread out across North America. How are the cases connected? In the aftermath of Hirass death, David is determined to expose the fraudulent reverend from episode 3. David suspects his old friend Danny, a hockey player, is using a dangerous performance-enhancing steroid.

NorBAC reviews an experimental treatment being used on children with Leukemia. Just as they are about to declare the cancer therapy safe, another child dies. David disregards the proper channels and goes to Nunavut to get a sample of what he believes is the Spanish Flu virus from a frozen corpse. Mick and Lilith go whale-watching in Quebec, but Lilith begins to realize just how sick he is.

A major power blackout on the Eastern Seaboard leads to fears of terrorist activity. NorBAC determines that a plastic eating bacterium caused the blackout and they must stop it before more blackouts occur. David and Liliths mother, rekindle old animosities when she comes to town to help Lilith deal with Micks death. Caroline is worried about the possibility of having breast cancer. Bob Melnikov, NorBACs Biochemist tells David he has been approached with another job offer.

In the continued investigation of the "Iraq War Syndrome," David checks out a theory that the water purification system has malfunctioned. In Mexico, Jill and Carlos make a connection between a hybrid plant designed to detect land mines and the hemophilia epidemic. When that theory fails, David joins them in Mexico and explores the possibility that mosquitoes bred to eliminate malaria might be responsible. Bob quits NorBAC to pursue his love of perfume creation. Caroline receives the diagnosis shes been waiting for.

David and Jill make a trip to Colorado where a rampant SARS-like outbreak is occurring. David is in shock when he discovers that the outbreak is Spanish Flu, the virus he dug up in Nunavut. Racked with guilt, he walks into the path of a car and is sent to hospital in a coma before he tells anybody his fears. Mayko Tran heads to Colorado to try to find Patient Zero.

After a self-imposed exile to China, David Sandström is kidnapped by the Peoples Liberation Army and ordered to secretly investigate a deadly outbreak that has killed 19 people in a small village. With the help of three Chinese scientists, David discovers the outbreak has been caused by an ancient bacterium that has seeped into the villages water system. David is horrified when he learns that one of the scientists has decided to test the antidote on her self in order to expedite a cure. While David makes his way back to Canada, Caroline and Carlos are witness to a horrific attack at the site of the International AIDS Conference.

The HIV strain that sean gave to Audrey Graves is so virulent that none of the new tri-therapy drugs work on it. They decide, then, to try a combination with any type of drugs that exist with the help of all the labs that accept the offer. Audrey Gravess baby is HIV positive and they hope to eradicate the virus with a new combination. Carlos is still searching for Patient Zero in Africa. In the mean time, NORBAC also looks at the devastating effects of pryon disease on humans via the consumption of infected chicken.

Jills new treatment for juvenile diabetes is halted when she discovers than the stem cells hold a retrovirus that might endanger the patients. The research on what plagues the girl found in the subway tunnel continues.

David and Carlos are still investigating the poison that is affecting Charringas lemon crops in Florida, before the United States decide to bomb Cuba. Jill, on the other hand, asks Mayko to contact all the other labs using the same stem cells from Korea to let them know a retrovirus is in that strain. Bob offers to verify all the steps one more time with her and see if her findings are correct. Simon Jessup finding that Glenn responds to all the stimuli suggests that he undergoes brain surgery.

There is a series of suicides in Arkansas that Norbac is called to investigate. David tries to decipher the work of a friend who died in a car accident.

Despite Davids public statement that GMO fish has no bearing on some illnesses, the dad of a young boy is convinced that his son is ill due to eating a the mutant fish. When an entire squadron of national guard falls ill, bio-terrorism is suspected, the team must work on the case.

The antidote created to cure the national guards isnt doing its job properly as the guards fall even more ill with another disease. Caroline, still investigating what Weston did, finds that the White House is mixed into it.

NorBac must find a cure to a bacterium that will surely kill David and Bob if they do not succeed. They also need to engineer the cure so that it eradicates the bacterium that was probably transported by the wind after the explosion of the lab in Utah.

Mayko finds the missing link to the Sinatra syndrome; Owen tries to commit suicide.

Mayko tries to get rid of the pain shes feeling in her phantom limb; the team investigates the high level of mercury contamination found in Lake McGraw.

Several fires in British Columbia start. One of the action organizers calls NorBac in as several firefighters present strange symptoms. Craig, Rachels son, come visit her mother at NorBac. Both Mayko and Carlos are attracted to him.

David discovers that NorBac has been tapped by Riddlemeyer. The team must find what caused the bear to attack Craig with no reason as a human being is presenting the same symptom. To save Bobs eyesight, David decide on a peculiar procedure.

Fears arise that Carlos may have been infected with Crimean Congo Hemorrhagic Fever; after experimental surgery that improves his vision, Bob becomes hypersensitive to the emotions of others; Carlton comes under scrutiny when a magnetobacteria threatens the countrys electronic infrastructure.

Bob is back. His brain surgery caused an infection which leaves him in a bad shape when found. He is put into a medically-induced coma. The team travels to Mexico where an antibiotic-resistant strain of TB is killing the Zapatista Revolutionaries.

As if being HIV positive wasnt enough, Wes is infected accidentally with a needle full of Hepatitis C.

After an experimental treatment for Hep C nearly kills him, Wes quits NorBAC to enroll in a cutting edge HCV program in Stockholm; a racist city councilor claims his daughter was poisoned by Muslim extremists; the FDA is willing to fast-track some drugs in order to save an immune-deficient woman who was infected with smallpox.

A pharmaceutical company comes under fire when its newly-marketed immune suppressing drug triggers a high incidence of congestive heart failure; David attempts to find a replacement for Wes; Bob suffers a seizure that triggers romantic memories of a girl named Nina.

A terrorist cell infiltrates the NorBAC lab and forces the scientists to produce a deadly measles mutation to be used as chemical warfare.

When a young boy is murdered, forensic evidence leads the NorBAC team to investigate the unlikely existence of a prehistoric cat that disappeared from North America 10,000 years ago; a dramatic development complicates NorBACs plans to deactivate Ninas Jacobsons organ.

Season 4 finale. A glimpse into the future renews Davids determination to stop the birth of the first human clone.