Dexter Morgan is an elegant monster, and he’s also a complicated Gemini since he’s constantly at war with himself through his Dark Passenger. Gemini is a sign of duality often driven by the conflict between their intellect and emotions, describing Dexter perfectly. Normally, Geminis thrive on change and get bored quickly. However, Dexter forces himself to suppress this aspect of his Gemini-ness, because having a facade of stability and “cultivated affability,” as Dexter actor Michael C. Hall puts it, deters people from looking deeper into his life.
Geminis are not a fan of team sports, but Dexter’s bowling team is an important part of the veneer that hides the beast within. He even chooses a partner in Rita Morgan (Julie Benz) for the very reason that she isn’t intellectually challenging. All of this protects his alter ego, the serial killer of killers, from detection, with the exception of only the more sensitive characters in his orbit like Sergeant James Doakes (Erik King) and Detective Joey Quinn (Desmond Harrington).
It’s when the Dark Passenger takes the wheel where Dexter is in his true element, working alone as he vets and hunts down potential bad guys for his table. As a blood-spatter analyst for Miami Metro Homicide, every day brings a different puzzle for him to solve through trace evidence, occupying the rational side of his brain until his instincts take over. Geminis must learn to stop analyzing love, and Dexter’s struggle with this aspect of his humanity remains ongoing.