Romulan

The Romulans were a race of aliens descended from Vulcans, who engaged in a mass exodus during the time of the Vulcan Reformation. The Romulans eventually settled on the planet of Romulus and began building the Romulan Star Empire, a political entity that would eventually become one of the major powers adjacent to the United Federation of Planets. (Memory-Alpha)

In 2339, Romulan agents built and occupied a hidden outpost on the Federation colony world of Carina VII, using it to study the temporal anomalies disturbing the planet. (1.1: Entropy's Demise)

The following month, Romulan ships attempted to recover torpedo technology that had been stolen by an Angosian scientist and passed off as his own invention. (1.2: That Which Is Unknown)

Shortly thereafter, a Romulan warbird disabled the Federation starship USS Ellesmere (NCC-21464) after the starship wandered into the Romulan Neutral Zone. Though initially understood to be an accident, it was subsequently discovered that the Ellesmere's breach had been the result of a Romulan spy onboard attempting to flee back to Romulan space with stolen intelligence. (1.3: Border Dispute)

Appearances
1.1: Entropy's Demise

1.2: That Which Is Unknown

1.3: Border Dispute