Defenitely one of the darkest and most eerie episodes of the series. Macgyver is sent in to the wilderness to recover an organism which has mutated after falling back to earth. To his horror, Macgyver sees the organism has completely decimated any wildlife in the area. Working against time, as the whole area was ordered to be firestormed, Macgyver narrowly escapes and is able to make it out alive. The organism is brought back to an underground lab in the Phoenix West division where Pete and Mac encounter its creator, Dr. Milhouse. She is the very defention of a "mad scientist", who is able to see only the potential of her work while ignoring it's dangerous faults. The writers do a good job making it known this is here lifetime work, and we can she how it is possible for her to be so blinded by the facts.
Soon the government orders the organism is to be destroyed, Milhouse reluctantly agrees, and all seems well. Or does it? The final 10 minutes are best not spoiled here but make it one of the better episodes in the season.