A Fragile Peace: The Neutral Zone Campaign Vol. 1 (1998)

From the back cover:
"A disputed border, an age old enemy, a fragile peace

For over fifty years, the Federation has enjoyed an uneasy peace with the Romulan Star Empire. The cornerstone of this fragile accord has been the Neutral Zone, a buffer one light year wide that separates the two galactic powers. Although each side has tested the other's resolve in the past, the ramifications of a large-scale violation of the Zone have been unthinkable. Until now...

Rumblings can be heard from the Romulan home systems once more, as shadowy political wheels begin to turn and hidden plans are set in motion. Fleets move in the inner systems and warbirds patrol the border. Some within the Imperial Senate whisper that the Tal Shiar – the sinister Imperial intelligence arm – are behind these stirrings. Others speak of a power-mad senator and his personal armada. Do you have what it takes to discover the truth and avert certain war? Will you be able to maintain... the fragile peace?

• A detailed look at the Arteline Sector, including the planets, outposts, characters and politics of this volatile region along the Neutral Zone border.
• A glimpse into the hidden machinations of the Tal Shiar, the elite intelligence service of the Romulan Star Empire.
• Four complete adventures, beginning a year-long campaign arc set in this tense and exciting region.
• In "Aiding and Abetting," the players discover a disabled merchant vessel crewed by Orions who aren't what they seem.
• "Marie Celestial" introduces a derelict Warbird whose silent corridors are filled with its dead Romulan crew.
• "Blinded by Science" follows a Federation science team as they test experimental new sensor equipment on the players' ship.
• "Armistice" takes the players planetside on Psellus III, a young world plagued by rebellion that is currently petitioning for Federation membership."