Mercury square Pluto (orb 1.6°) creates concrete friction between the two planets. The orb is very tight; this describes a stable character pattern more than a passing reaction.
Here, Mercury in Libra in House 12 brings intellect, language, thought, and technique into House 12 (retreat, contemplation, long time, and possible confinement), with Libra style (relationship, balance, negotiation, and sense of form); Pluto in Cancer in House 9 brings crisis, power, survival, and regeneration into House 9 (vision, belief, study, and wider horizons), with Cancer style (memory, protection, belonging, and family sensitivity).
Concrete friction: this aspect creates tension between thought, obsession, secrecy, and control: analysis can become too suspicious, harsh, or focused on crisis. Visible angle: Mercury near the Rising sign (orb 3.4°) and Pluto near the Midheaven (orb 4.9°) touch angles; this aspect is easier to notice through first impression, body language, reflexes, and entry style; also through social role, reputation, career, and public image. House 12 (retreat, contemplation, long time, and possible confinement) is in friction with House 9 (vision, belief, study, and wider horizons); this can create blockage, inhibition, overreaction, or repeated conflict between the two fields.