The Tal Shiar was the intelligence gathering agency of the Romulan Star Empire during its height, and in the years since the destruction of Romulus has evolved to become very nearly its primary military force. The Tal Shiar is notoriously ruthless and secretive, stopping at nothing to defend the Empire's interests. The Tal Shiar's covert operations are a constant source of fear and paranoia throughout the Alpha Quadrant.
The vast majority of hostile Romulan NPCs encountered in the game are affiliated with the Tal Shiar.
- “Virinat, Invaded”: The Tal Shiar and the Elachi allies invade Virinat and abduct or kill most of its inhabitants.
- “Flight from Virinat”: The player saves several escaping colonists from the Tal Shiar.
- “The Helix”: The I.R.W. Sharrdar, I.R.W. Koval, and several other warbirds attack a Suliban Helix in the Suliban System.
- “Crossroads at Crateris”: The Tal Shiar and the Elachi attack Crateris, though much of the population manages to escape with the player's help.
- “Turning Point”: Tal Shiar forces attempt to sabotage a conference being held by the Federation and Klingon Empire on Khitomer to discuss recognizing and supporting the Romulan Republic.
- “Project Nightingale”: Chief Interrogator S'rall attempts to interrogate Commander Ran Meru of the U.S.S. Nobel on Cirini Prime.
- “Mine Enemy”: The Tal Shiar operates Listening Post Hephaestus out of the moon Khoal in the Hfihar System.
- “Frozen”: Obisek of the Reman Resistance reveals that the Tal Shiar no longer serves the Empire; they have instead turned to the "demons of air and darkness". Shortly after, Tal Shiar forces besiege the Remans' base on Dera IV.
- “Coliseum”: Colonel Hakeev has established a base on Nopada Prime, which he uses to study the behavior of various cultures and find the best way to turn them against each other.
- “Cutting the Cord”: A Tal Shiar base in the Brea System comes under attack from Obisek's forces.
- “New Romulus: Staging Area”: Players occasionally encounter undercover Tal Shiar agents attempting to infiltrate the nerve center of the New Romulus colonization efforts.
- “New Romulus: Vastam Peaks”: Tal Shiar agents harass Avran's scientists in the Vastam Peaks of New Romulus.
- “Carraya System Patrol”: Forces of the Tal Shiar attempt to occupy the Carraya System.
- “Acamar System Patrol”: The Tal Shiar engineers a dispute between two Acamarian clans. If the player successfully resolves it, the Tal Shiar attacks them.
- “Hidden Camera”: Subcommander Khiana attempts to bribe D'Tan, but is rebuffed.
- “New Romulus: Mountain Base”: The player is tasked with eliminating a Tal Shiar base in the mountains near Vastam Peaks.
The Tal Shiar uses generally the same assets as the Star Empire, though some of its ground forces are labeled differently.