The story of the history of our universe, but with too much unmotivated technical detail and not enough context.
I love technical details when they're explained well, but Hawking often dives into details without ever framing them with why they're relevant.
The readability wasn't great either - I was hoping for a narrative about the history of the universes creation with technical details to fill the gaps, but instead it was mostly several losely strung together technical details without much broader context.