Theseus is a former Prothean system. Three of its five worlds bear evidence of Prothean development. In modern times, ExoGeni Corporation has staked a claim on the ruins of Feros while the others are bereft of anything valuable, cost-ineffective for meaningful resource exploitation, or not thoroughly explored.

Feros

Feros is the second planet orbiting the star Theseus.

Main article: Feros

• Mission: Feros: Geth Attack → Feros: The Thorian → Feros: Colony Saved | Feros: Colony Gone
• Assignment: Feros: Data Recovery
• Assignment: Feros: Geth in the Tunnels
• Assignment: Feros: Power Cells
• Assignment: Feros: Varren Meat
• Assignment: Feros: Water Restoration

Logan

Logan is the fifth planet orbiting the star Theseus.

Main article: Logan

Quana

Quana is the fourth planet orbiting the star Theseus.

Main article: Quana

• Survey: UNC: Valuable Minerals: Light Metal ×1

Sharring

Sharring is the third planet orbiting the star Theseus.

Main article: Sharring

• Collection: UNC: Prothean Data Discs: Prothean Data Discs ×1

Sytau

Sytau is the first planet orbiting the star Theseus.

Main article: Sytau

Trivia

• The system is named for the mythological Greek hero Theseus. Theseus was said to have slain the Minotaur in the Cretan Labyrinth.