In Arlington, Texas, a 7-year-old budding baseball star might be playing his last game when a mysterious infection takes over his brain. Suffering violent and uncontrollable seizures, the situation leaves his parents traumatized.

A man suffers from an infection that's shutting down his organs.

A 7-year-old girl suffers from mysterious seizures and painful rashes and winds up in a deadly coma. And a yoga-loving college graduate's health spirals viciously out of control when "the flu" turns out to be a flesh-eating monster.

A teenage ballerina suffers debilitating migraines and muscle failures.

A newly engaged man is forced to choose between amputation or death.

A mother of four struggles with a mysterious lump that emerges on the neck of her two-year-old daughter. But as doctors quarantine her, it's a race against time to save her life.

An oil rig worker in Nikiski, AK, is struck down by bizarre hallucinations.

A deadly organism strikes a volunteer while she's in West Africa.

A teenager dodges death when he survives getting sucked into a tornado. When his trauma wounds mysteriously don't heal, doctors discover a hideous infection.

Three families enjoy the bounties of nature, and all of them suffer its wrath. A young girl's love of swimming comes back to haunt her when she develops severe headaches, nausea, and a bizarre rash all over her body. The cause sends everyone reeling.

A couple comes home for Christmas and finds stowaways that consume flesh.

Three deadly illnesses darken the futures of three young boys. In Illinois, a mother thinks her newborn son has something wrong with his eyes. When doctors analyze the boy further, they discover something is eating his eyes and brain.

Three women in different locales have one thing in common: they've become unwitting hosts to baffling & deadly terrors. A teenage girl thinks she's losing her mind, but she actually has a life threatening inflammation of the brain.

When three unsuspecting young families are thrown into a tailspin, they are shocked to learn of the tiny culprits wreaking havoc on their lives.

A Massachusetts EMT is shattered by a routine emergency call when she discovers that the victim is her son and a self-described tough guy in New Jersey is reduced to tears when something sinister starts to rip apart his intestines.

A contractor bumps his head while working & days later finds himself in the ICU fighting for his life. A college football player is in agony from blinding headaches, and a boy is enjoying summer when a mystery illness takes hold.