This study analyzes grief in Franzen’s novels through a neurocritical lens, examining its portrayal of brain–heart dynamics and emotional arousal. This neurocritical analysis explores how grief in Jonathan Franzen’s The Corrections (2001) and Crossroads (2021) engages brain–heart dynamics, particularly the amygdala’s activation and its influence on heart rate variability (HRV), a physiological marker of emotional arousal. Through close textual analysis, affective neuroscience insights, and reader-response theory, we examine scenes of familial loss (e.g., Alfred Lambert’s Alzheimer’s, Marion Hildebrandt’s trauma) to hypothesize amygdala-mediated emotional responses accompanied by an increased low-frequency to high-frequency ratio in HRV. Franzen’s realist style fosters empathy, mirroring the real-world processes of grief. The findings suggest therapeutic implications for emotional regulation. Limitations include the study’s theoretical approach and the absence of empirical data. Overall, this study bridges literature and neuroscience, contributing to medical humanities and interdisciplinary scholarship.