WARNING: The following contains spoilers for Eden, now streaming on Netflix.
In Netflix's Eden, the villainous robot Zero cuts a very intimidating figure. He's aiming to kill all the remaining humans in the 30th century as they lay in cryo-pods. A mix of Darth Vader and Ultron, Zero wants robots to keep ruling the planet in the bastion known as Eden Three -- a cyber paradise he's worked hard to achieve with his A.I. advisor, Geneva.
However, as the four-episode series unravels, we discover there's a tragic reason behind Zero's hatred for humans. The revelation comes with direct ties into the past of the man who created him, Dr. Weston Fields, and the fact that they are, in fact, one and the same.
In Eden, Sara is on a quest to wake the hibernating humans up as time's running out for their stasis pods. However, after getting called to Eden Three and then exploring another camp, Eden Zero, Sara pieces together clues on the link between Fields and Zero. Using a previous iteration of Geneva's A.I. known as Zurich, Sara discovers Fields was once the human in charge of creating the concept of Eden. Back then, it was meant as a garden where robots would grow crops such as apples, helping humans achieve a clean world of sustainability.
Many significant issues plagued the world of Eden, including war, violence, pollution and societal ills, which rendered the planet uninhabitable -- placing humanity on the brink of extinction. Still, Fields' mission went beyond saving the world and was much more personal as he also wanted to cure his sick daughter, Liz. So Fields built the pods to store healthy folks, as well as non-contagious people, like Liz, so that while everyone slept, his robot minions and A.I. could work to create a cure for the mysterious illness. Then, once they woke up 400 years later, he could heal her, making amends for failing to save his wife, Ashley, who died after falling ill.
Unfortunately, things didn't go as planned, and the major reveal is that Fields lost them both, which led to him transplanting his mind into a robotic body -- becoming Zero. Sara uncovers the intel from Liz's robot dog, Emily, learning that the young girl died from her disease, meaning Fields ran out of time. Meanwhile, Ashley was being cared for at St. Irene's and seemingly perished when the hospital was attacked by gunmen fighting for resources. This grew Fields' hatred of humankind, believing they were animals who believed only in bullets and bombs and not peace and progress.
After suffering the loss of his family, Fields had Zurich (Ashley's evolving consciousness in A.I. form) store away his memories and implanted him into Zero. He shared a similar experience to Sara, waking up early in his pod, but instead became a tyrant that wanted to ensure the pods never activated again to ensure his new vision of paradise continued.
Fields/Zero couldn't harm humans directly as a robot, so he hid away the password Sara would need to unlock the pods. This way, he could let the timer run out on the pods, so the 34,998 people stored would all die a natural death. To Zero, a world without humans was the only way to save the planet and create the utopia his daughter always dreamed of.