"I have Pluto in transit opposing or squaring Mercury in the birth chart. What is involved ?" What can it mean to have bad form Pluto aspects such as quadrature and opposition with our natal Mercury ? What a way to give an unfavorable passage of Pluto on the planet Mercury in our birth chart ? What does it mean to have the planet Pluto square or opposed natal Mercury ? The transit of Pluto quadrature and opposition to natal Mercury which carries positive connotations for us ? Which are meaning, significance, sense of the planet Pluto in transit in square or opposition at the birth Mercury ? Having this planet in bad aspect and then square (90 degrees) or that form an opposition (180 degrees) with the planet Mercury can bring important significance not only on a personal level. Let's say, however, that not take into consideration the position of Mercury in the 12 astrological houses and then Pluto transiting Mercury which is in I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII house. This is because Pluto is a generational planet, and therefore its influence rather than on the individual and therefore on its areas of life takes place and acts on an entire generation, an entire community.
Meaning : be careful because it is easy to drive you undergo an accident. Behave in a more correct manner with others without being overly arrogant because you could be subject to lawsuits. Possible problems by brothers, sisters, relatives who might commit crimes.