Context:

Tom explicitly mentions this as the book they are discussing in the episode. He says he read it on a holiday in Greece about three or four years ago. The book argues that climate and disease played a major role in the fall of the Roman Empire.

Context:

This is the guest Kyle Harper's book that forms the basis of the podcast discussion. Tom explicitly names the full title near the end when praising it as 'a brilliant work of history' that is 'stylistically brilliant' and 'wonderfully well written.'

Context:

This is the main book being discussed in the episode. The hosts quote from it and introduce it as 'a brilliant new book' about the history of infectious disease and human history.

Context:

Mentioned as a previous book by the guest Kyle Harper, described as 'a fantastic book in which he looks at how disease impacted on the fall of the Roman Empire.'