Day One Ending Explained: When Ulises finds out about a program that can change the way we perceive free will, he jumps in to stop the technology from going live to the public before it’s too late.
Day One Prime Video Cast
Álex González, Iván Massagué, Alba Planas, Jordi Mollà, Renata Notni, Asier Etxeandia, Mireia Oriol, Melina Matthews, David Janer, Peter Vives, Àgata Roca, Mercè Martínez, Oscar Muñoz, David Selvas
Day One Series Director
Marta Pahissa, Víctor Cuadrado
The Spanish series has 6 episodes, each about 40 minutes long.
Day One Ending Explained
The series opens with Ulises, a brilliant computer engineer, having left everything behind after his sister’s suicide, getting a message from his friend Samuel Barrera one fine day about an old invention of theirs threatening to wreak havoc. Confused, Ulises immediately comes back and meets Samuel, but before he can understand what’s happening, he is killed by an assassin.
On the run, he realises that Samuel has hidden away the code to this dangerous invention somewhere, but he is not sure where. This pushes him to learn more about what is going on with Diskin, the company allegedly behind everything, and he teams up with Rebecca, a woman who accidentally got pulled into this mess after she took a video of him and the assassin one day, to learn more about the plot.
What is the technology?
The technology that Ulises and Samuel had created focused on understanding people’s emotions and controlling them before they could take extreme action. Another scientist, Beth, had worked on this programme and expanded it, inserting a microchip in contact lenses and hacking into the brain in order to control it. However, this, of course, came with its own ethical problems, especially when it became clear that Damian was trying to use the technology to control people and take away their free will.
Does Ulises stop it?
After much struggle and losing close ones in the process, Ulises stops the Day One program from launching to the masses after Beth changes sides and exposes the illegal testing methods during the launch event. It brings the truth in front of everyone and leaves them shocked, and soon after, the police arrest Damian for killing Samuel and Paula.
In the end, Ulises accomplishes his goal and eventually finds Anna’s hologram that Samuel had created, which gives him the closure that he needs to overcome that one last hurdle.
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Also Read: Day One Review (2026): A Strictly Mediocre Series That Somewhat Entertains