Question: What country was the theatre that premiered The Power of the Fiend located in?

Context paragraphs:
Mariinsky Theatre: The Mariinsky Theatre (Russian: Мариинский театр , Mariinskiy Teatr, also spelled Maryinsky or Mariyinsky) is a historic theatre of opera and ballet in Saint Petersburg, Russia.  Opened in 1860, it became the preeminent music theatre of late 19th century Russia, where many of the stage masterpieces of Tchaikovsky, Mussorgsky, and Rimsky-Korsakov received their premieres.  Through most of the Soviet era, it was known as the Kirov Theatre.  Today, the Mariinsky Theatre is home to the Mariinsky Ballet, Mariinsky Opera and Mariinsky Orchestra.  Since Yuri Temirkanov's retirement in 1988, the conductor Valery Gergiev has served as the theatre's general director.

The Seven (play): The Seven is a play written in 2005 by playwright, Will Power.  In 2001, The Seven premiered in San Francisco as One Act and premiered in the New York Theatre Workshop in 2006.  This play is a modernized version of the old Greek tragedy, Seven Against Thebes written in 467 B.C by Aeschylus.  Will Power revives the story about King Oedipus' sons, Eteocles and Polynices fighting to gain control over the city of Thebes.  Setting the ancient tragedy in a more urban setting while incorporating modern lifestyle into play, the audience was able to relate to the performance.  The play leaned more toward comedy rather than a traditional tragedy.  Fueled by spoken word, hip-hop, soul, funk, R&B and a capella, set the play to a modern American experience.

Sultan Salahuddin Abdul Aziz Power Station: Sultan Salahuddin Abdul Aziz Power Station (Malay: "Stesen Janaelektrik Sultan Salahuddin Abdul Aziz" ) is a power station, which fires natural gas, bunker oil and coal, located in Kapar, Klang District, Selangor, Malaysia.  It was opened in March 1987 by then Sultan of Selangor, Sultan Salahuddin Abdul Aziz Shah, and the station was named after him.  In terms of power producing capacity, it remains the largest power station in Malaysia, despite the commissioning of several new power stations with 700MW steam turbines.  It is also the first coal-fired power plant in the country.

Another Country (play): Another Country is a play written by the English playwright Julian Mitchell.  It premiered on 5 November 1981 at the Greenwich Theatre, London, and transferred to the West End in March 1982.  The play has developed a strong connection with Oxford Playhouse, which revived the play in 2000 in a new production directed by Stephen Henry (transferred to the Arts Theatre, Westminster, from September 2000 until January 2001).  It was revived again at Oxford Playhouse in February 2013 by OUDS-supported Oxford University student company Screw the Looking Glass.  In September 2013 a successful collaboration between Theatre Royal Bath and Chichester Festival Theatre was directed by Jeremy Herrin, transferring to Trafalgar Studios in 2014.

Gariuai Hydroelectric Plant: The Gariuai Hydroelectric Plant is a run-of-the-river micro hydro power plant located in the town of Gariuai in Baucau District, East Timor.  It is the only operational hydroelectric power station in the country.  In order to reduce dependency on diesel generators, sites were surveyed in 2004 in Baucau District for a hydroelectric power plant.  Two streams, Builai and Wainalale were selected to provide water to the power station.  Construction began in 2006.  A 2 m tall embankment dam was constructed on Builai stream and a second 1 m high dam was built on Wainalale stream.  Connecting the dams to the power station is 2200 m of penstock.  A single 326 kW Pelton turbine-generator is located in the power station which was commissioned in November 2008.  The elevation between the reservoirs and the power station affords a hydraulic head of 196 m .  The project cost US$1.4 million which was funded by a grant from the Norwegian Water Resources and Energy Directorate.

Prime Stage Theatre: Prime Stage Theatre is a professional theatre company located in Pittsburgh, Pennsylvania, USA creates a blend of educational programs and theatrical productions families, middle school and high school students, educators, and theatre patrons.  Its mission is to "entertain, educate, and enrich families, students, and educators in the discovery of live theatre and literature...by producing adaptations of literature, new works, and programs that address relevant topics of teens and adults."  Founded in 1996 by artistic director Wayne Brinda, the company has produced over 65 productions including 9 world and regional premieres and three scripts that are published and produced around the country.  The theatre's first production was "A Woman Called Truth" staged at the Station Square Playhouse.  The theatre then moved to La Roche College, where it produced two full seasons.  In 1998, the theatre moved to Pittsburgh Civic Light Opera Academy for one season, followed by its production of "Clemente: The Measure of a Man" at Point Park University's George White Theatre in 1999.  In 2000, Prime Stage produced works at the New Hazlett Theatre, until it inaugurated a new theatre facility at 937 Liberty Avenue in 2003, a space now inhabited by Bricolage Production Company and Pittsburgh Playwrights Theatre Company.  In 2006, Prime Stage returned to the New Hazlett, where it has continued to produce theatrical adaptations of literary classics and classic plays.  Prime Stage has also staged productions as part of the Pittsburgh New Works Festival.

The Power of the Fiend: The Power of the Fiend (Russian: Вражья сила , "Vrazhya sila") is an opera in five acts by Alexander Serov, composed during 1867-1871.  The libretto is derived from a drama by Alexander Ostrovsky from 1854 entitled "Live Not As You Would Like To, But As God Commands".  The opera was premiered posthumously on 19 April 1871 (Old Style) at the Mariinsky Theatre in Saint Petersburg under Eduard Nápravník.  Among the performers were Darya Leonova as Spiridonovna and Mikhail Sariotti as Yeryomka.  Although in many ways it is more far-reaching than Serov's previous two operas, this work was not a success.

The Unconquered (2007 play): The Unconquered is a play for four actors by Torben Betts which premiered at the Byre Theatre, St Andrews in February 2007 before touring the United Kingdom (venues including the Tron Theatre in Glasgow, the Traverse Theatre in Edinburgh and London's Arcola Theatre.)  It received critical acclaim and won the award for Best New Play at the Critics Awards for Theatre in Scotland, 2007.  Keith McIntyre's cartoon-like design was nominated for an award at the same time.  The production was remounted in 2008, and toured the country again before taking part in the Brits-off-Broadway Season in New York City followed by Trap Door Theatre's production in Chicago.

Talcher Thermal Power Station: Talcher Thermal Power station is located in Talcher sub-division of Angul district in the Indian state of Odisha Pin.759101. The power plant is one of the coal-based plants of NTPC.  The coal for the power plant is sourced from Jagannath Mines of Mahanadi Coalfields Limited.  Source of water for the plant is from Brahmani River. This power plant has been ranked among the best power plants in the country despite being the oldest plant in the state.  It has consistently topped the charts in NTPC for the last 4 years and was also the nation's top power plant (by PLF) in 2015-16.

Spokane Civic Theatre: Spokane Civic Theatre is a nationally recognized non-profit theatre located in Spokane, Washington.  Incorporated in 1947, the theatre is one of the oldest community theatres in the country.  In recent years, the theatre has been brought to a level of excellence that has resulted in many awards.  The theatre's mission is "to foster and operate a volunteer live community theatre of high artistic merit."  Civic, as it is fondly called by the surrounding community, sets a high standard for theatre in the Spokane area.

Supporting paragraphs: The Power of the Fiend Mariinsky Theatre
Answer: Russia