After Maggie helps Rachel successfully deliver her baby, the killer strikes again -- and XX's identity is revealed.

After a forceful seizure of power, the subjects attempt to escape the facility. At Portlaoise, Arthur receives an unexpected visitor.

The participants suddenly get sick just as the computers are infected with ransomware. Arthur does Patrick's dirty work in exchange for a cellphone.

Distrust mounts as the base's supplies continue to be tampered with. At Portlaoise, Arthur receives a letter from the anonymous admirer "XX."

After a team member is stung by a scorpion, the others suspect sabotage on the base. Two years earlier, Arthur struggles to gain respect in prison.

In the lawless desert territory of Bir Tawil, a group of scientists carry out the next phase of Wilde's research: testing the bacteria on humans.