Day One — Season 1, episode 1 watch online

Day One, season 1 episode 1 «Samuel»: air date March 13, 2026. Episode overview, season trailer and the cast of Day One.

After years in isolation, Ulises returns to Barcelona when his former partner asks for help decrypting Pandora, the code behind a revolutionary technology. The reunion ends in murder, turning Ulises into the main suspect. As a video of his escape goes viral, tech mogul Damián Diskin prepares to launch Day One, and Ulises realizes that nothing - not even his friend's death - is what it seems.