And Charlie also has his own plans as concerns Irina. He isn't quite certain what this new weapon technology is all about (Sam considers that information to be on a "need to know" basis, and doesn't think Charlie needs to know), but he wants to know exactly what's going on before he actually does Sam's bidding. In fact, Charlie anticipates that whatever he does, Sam's going to suffer before he's done. So he immediately drops off Sam's radar and starts tracking Irina on his own. Panicked, Sam brings in his contingency plan earlier than he expected: a brutal South African mercenary and his team of vicious thugs.

The story really gets interesting when Charlie hooks up with Irina. The Russian agent doesn't quite know what hit her when this smooth-talking silver fox suddenly shows up at the house of a man whose truck she was trying to steal. But Charlie "read" her right, and he knew which way she was heading despite all of her misdirection. The game between them - because she is, in her own way, just as competent as he is - is ultimately at the heart of the book.

Charlie isn't a superhero and he isn't Sherlock Holmes (at least, not quite). But he is, at least in one sense, an heir to Holmes' supposed "power of deduction" because of his ability to accurately conduct a "cold reading" of someone. As Garber himself explains the concept on his website:

No different from a good salesman (or a good con artist), WHIRLWIND's hero, Charlie McKenzie knows how to deduce personal information from people's physical appearance, clothing and accessories, vocabularies, and body language. In other words, Charlie is a "cold-reader" ---- he employs the same methods professional magicians (and others of less reputable trades) use to convince their audiences they have psychic powers.

Cold-reading works best when you're face-to-face with your victim because an important part of the methodology is feedback. That is, the cold-reader draws a tentative conclusion, then ambiguously bounces it off his victim. How the victim reacts tells him all that he needs to know.
. . .
More than anything else, feedback lies at the heart of effective cold- reading. However, cold-reading begins with quick and observant study of your victim. Here's what Charlie McKenzie thinks about the first time he sees someone new ---- and the questions he asks himself.

Charlie's questions include such things as whether the person is of foreign background; how the person is dressed, what he or she looks like, be it clothes, hairstyle, or the like; the presence of a ring, facial hair, even the condition of their shoes. It isn't just that he observes such things: he also knows what they might suggest on a psychological level. Just a review of Irina's record allowed him to see the frosty relationship she had with her father, based upon her clothes, a hint of body language, and the fact that she didn't like to participate in sailing with her family.