Here’s the book’s synopsis:
“Captain’s Log, Stardate 42802.3. We have diverted to the Zeta Gruis system in response to a distresscall from its seventh planet. Previous surveys have shown the planet to be uninhabited, abandoned by its native civilization as its star swelled into a red giant. The distress call appears to come from a city in the southern polar regions, still cool enough to be habitable. We may be about to encounter the last remaining natives – or just some interstellar scavengers or archaeologists. The distress call gives no specifcs about the nature of the threat.
However, Zeta Gruis is not far from the Romulan Neutral Zone, and it has been less than a year since the Romulans emerged from isolation and adopted a newly aggressive stance. They have not yet ventured this far into Federation space, but we’re keeping our guard up anyway”