Here's what we know:
* No official confirmation: As of now, there's no official announcement from James A. Owen or his publisher about a third book.
* Author's interest: Owen has expressed interest in exploring more of the Imaginarium Geographica world, suggesting that there could be potential for future installments.
* Fan demand: There's a passionate fan base eager for a continuation of the series, which could influence Owen's decisions.
In conclusion, while a third book hasn't been confirmed, the possibility exists. It's best to keep an eye out for any official announcements from the author or his publisher. You can also join online communities dedicated to the series to stay updated on any developments.