[qilo]

Here's what ChatGPT 4o mini (free) answered to me to the same question:

No, Paul Edwin Zimmer did not write a fourth novel in the Dark Border series. The trilogy consists of "The Dark Border," "The Dark Border: The Return," and "The Dark Border: The Reckoning." After these, he focused on other projects and did not continue the series.

[pama]

ChatGPT with search:

Yes, Paul Edwin Zimmer wrote a fourth novel in his Dark Border series titled Ingulf the Mad, published in 1989. This installment focuses on the characters Ingulf Mac Fingold and Carrol Mac Lir, detailing their meeting and the acquisition of their mystical swords. Notably, Istvan Divega, the protagonist of the earlier books, does not appear in this novel.

[ta-run]

Here's o1-preview after thinking for 7 seconds,

> As of my knowledge cutoff in October 2023, Paul Edwin Zimmer did not publish a fourth novel in the Dark Border series. The series comprises three books: > 1. The Lost Prince (1982) > 2. King Chondos' Ride (1982) > 3. A Gathering of Heroes (1987) > > Paul Edwin Zimmer had plans to continue the series, but he passed away in 1997 before any additional novels were completed or published. There have been no posthumous releases of a fourth Dark Border novel. If there have been developments after October 2023, I recommend checking recent publications or official announcements for the most up-to-date information.