The episode introduces a "slow-motion catastrophe" through the perspectives of characters across the globe:
Rather than focusing on immediate explosions, the episode uses a haunting score by Max Richter to build a sense of "beautiful dread". [S1E1] Last Day
A communications specialist at JASA whose world is upended when a shuttle mission involving her secret lover, Captain Hinata Murai, meets a catastrophic end in orbit. Critical Reception Reviewers at TV Obsessive noted that
The "invasion" is initially secondary to the personal crises—infidelity, retirement, and forbidden love—of the people experiencing it. Critical Reception inexplicable crater in a cornfield.
Reviewers at TV Obsessive noted that the episode feels more like a character drama than a traditional sci-fi thriller, drawing comparisons to The Leftovers for its focus on the emotional aftermath of the inexplicable.
The tone is set immediately in S1E1 (“Last Day”), less by the cold open in Yemen and more by the credits sequence that follows it. TV Obsessive
A weary Sheriff on the verge of retirement who investigates a massive, inexplicable crater in a cornfield.