Charlotte Holmes was trained from an early age to depend on her intellect. Her mind is as sharp as a scalpel, but other aspects of her temperament have been neglected. In contrast, James is of average intelligence but has a high level of emotional intelligence and an overactive conscience. As a result, the two friends find themselves in a constant tug-of-war between mind and heart. Charlotte is all mind, while James is all heart.

The novel makes some attempt to sharpen James’s observational skills when Charlotte repeatedly tries to teach him how to find evidence or how to know when someone is lying. However, the greater challenge seems to be teaching Charlotte how to feel. This isn’t simply a matter of prioritizing emotion over logic. Rather, Charlotte’s disastrous infatuation with August taught her to mistrust herself. Because she doesn’t know how to channel her emotions appropriately, her anger at being rejected develops into a desire for revenge.

Given her formidable intellect, Charlotte had no difficulty setting up a drug drop and making August and Lucien take the fall. She later tells James, “What my mother was afraid of was sentiment. […] Of my being sentimental.