In the parahuman species-meld program, you either live, or you don't. If you don't, bad luck. If you do, well, you get the benefit of having your DNA genetically fused with that of an animal, giving you certain strengths and attributes normal humans couldn't gain otherwise.
Victoria Kaelin administers the serum that adjusts the DNA little by little, but she begins to notice particular aggressive behaviours emerging when her ruthless program leader decides to "fix" the serum. She turns to her best friend, parahuman Lux Matthews, for help, but upon investigation, their lives are flipped out of favour. Nothing is an accident anymore, and they struggle to survive the suddenly perilous life they've gained.
Season 4 of The Virus Within
Trinity is familiar with zombies, being one herself, but when strange zombies start appearing, she realizes that the world she knew might be changing yet again.
When a dangerous set of scientific notes are discovered, Trinity and her friends don't realize anything is wrong until a frantic radio call comes in. Unaware of the notes, they race to the south and struggle to determine where the strange zombies came from. The zombies are unlike any ranks previously seen, and they aren't as predictable. Some have new tricks hidden up sleeves, forcing any Stronghold they encounter to quickly adapt to the new challenge or risk being overrun. Secrets never remain hidden, and zombie apocalypses never make life easy.