It seems there might be a misunderstanding in your question, as "burgh" and "plasma guard" aren't clear references. If you are referring to a specific character or event from a book, movie, or game, could you please provide more context or clarify your question? This would help me provide an accurate answer.
You must go to the city. Look for the gym. Go inside. Burgh will come out and say that he cant battle. Find him in Union Port. He will be with Bianca and Iris. Then go to the direction of the gym. Burgh will be there. He will run towards the gym. You will see him near 2 team plasma grunts. You will battle them and then he will go inside a building Ghetses will be there and will give a speech. Then, Burgh will go back to the gym. He is easy. He has Pokemon from level 21 to 23. Then, continue on your journey.
Chris de Burgh was born on October 15, 1948.
Hendrick van der Burgh was born in 1627.
Knut Burgh's birth name is Knut William Borg.
Knut Burgh died on April 23, 1965, in Svendborg, Denmark.
You have to deafeat the Nacrene city gym leader, Burgh, in order to get to pinwheel forest :o)
Edward Burgh was born in 1461.
Albert Burgh was born in 1593.
Albert Burgh died in 1647.
Burgh House was created in 1704.
Burgh Heath's population is 6,219.
Burgh Windmill was created in 1842.
James Burgh was born in 1714.
James Burgh died in 1775.
Jeroen van der Burgh's birth name is Jeroen van der Burgh.
Thomas Burgh of Gainsborough died on 1496-03-18.
Chris de Burgh is 62 years old (birthdate: October 15, 1948).