On Wed, 21 Apr 2021 12:22:15 +0000, Mike Duffy wrote:

Frederick Pohl. If you read the 'Eschaton' trilogy,
(5 books), be sure to do them in proper order.

Sorry to self-follow-up, but the 'Eschaton' trilogy was a trilogy.

And I just noticed at:

https://en.wikipedia.org/wiki/List_o..._Frederik_Pohl

that the 'Heechee' saga is six books, the last of which is new to me, so
thanks, AK. I'm sure I will enjoy reading it!