Sutra was a female android, and the twin sister of Jana. She was created by Doctors Bruce Maddox and Altan Soong in the late 2380s at Coppelius Station, Coppelius.
Sutra was well-versed in Vulcan culture, and learned to perform a mind meld. She melded with Agnes Jurati, to gain the information coded in the "Admonition". She then convinced her "brothers" and "sisters" to build a beacon and signal the ancient Synth beings, as a protection against the Romulans and Organics in general.
To make her point more convincing, Sutra killed Saga and set Narek free from captivity, staging it as if Narek had broken out and murdered his guard. She then ordered her fellow synths to take Jean-Luc Picard into custody. When Doctor Soong discovered Sutra's deception, he deactivated her. (PIC: "Et in Arcadia Ego, Part 1", "Et in Arcadia Ego, Part 2")