NOTICE: I did not create this theory, nor do I claim to be the first person to come up with this. This is just my /explanation/ of the theory (I first saw this on a social media page I don’t think I’m allowed to link- but credit to the original creator!) Spoilers for KOTLC- please read all eight books! Please don’t be offended if we disagree, this is just a theory! <3 So, those who have read KOTLC know that the Heart and Head Theory was first mentioned in the writings of Lord Cassius and basically states that people have different emotions in their head than in their heart, because “head emotions” are our conscious emotions, and “heart emotions” are our true emotions. When enhanced, Keefe (an Empath) can sense heart emotions instead of the head emotions he normally feels. The first time he is enhanced by Sophie, he feels her emotions and grins, a reaction he tells her later was him feeling her heart emotions (and presumably her unconscious feelings for him). Fitz and Keefe are also strongly linked to head and heart. Fitz is a Telepath and Sophie’s Cognate, and their minds are undeniably linked. Keefe, being an Empath, is more obviously linked to heart. He also sends “green breezes” when she’s stressed, and the inflicting pill to link Sophie’s infliction to her heart is also green. Fitz and Keefe’s respective roles are clarified in Legacy when Keefe says: “Fitzy can cover the head stuff, I’ll cover the heart stuff.” Some more evidence that this theory is legitimate? The super-awkward scene with Dex in which he realizes that although his /head/ thought he liked Sophie, his heart didn’t. This is what’s been happening between Fitz and Sophie, in my opinion. Whenever they share a moment, Sophie always describes her giddiness being marred by something feeling “off”. That’s her heart telling her that she and Fitz aren’t right for each other. When Sophie links her head and heart emotions (to fix her inflicting), she calls it a “fresh start”, which is very possibly referring to her relationships. This theory was introduced in Neverseen and has been hinted ever since, so we may get more clarification in Unlocked about what this means for the relationships in the series, but I’m definitely crossing my fingers :D