The first of three, Mercury/Pluto squares is coming up, as Mercury in Libra squares Pluto Rx in Capricorn (at 13 degrees) on September 9th. This is one of the repeat aspects that I listed in this post. When an aspect is repeated over the same degrees, there's going to be a recurring situation.
Mercury square Pluto is about verbal confrontation, verbal manipulation, or digging for information. Pluto is the shadow that creeps into your thoughts. Pluto burrows beneath, or stomps all over, polite, Libran statements. Sometimes, Mercury becomes the master manipulator, using Pluto's power to distort Libra's social grace.
If you have anything from 11 to 14 degrees of the Cardinal signs, stay alert. You'll be on the receiving end of a Mercury/Pluto jab, or you'll be attempting to wrangle this energy through your own words. Whether you're giving or receiving, know that distorted interpretations of what's being said (they said A but really meant B) are a risk. This is the aspect of suspicion.
The best use of this energy is to listen; instinctive understanding will be high, if you can avoid being compromised by paranoia or anger. Also, know that Pluto always bites back when you respond with aggression, or attempt to use its power as a weapon. Pay attention to what you suspect/learn, but think before you say anything. Pluto's compulsive push can result in verbal evisceration, even if you think you're being nice and moderate.
Mercury Rx will square Pluto Rx at 12 degrees, on September 24th. And Mercury direct will square Pluto direct at 13 degrees, on October 22nd.