My protagonist, Lauren Rousseau, is a Linguistics professor. We find out that she speaks Japanese and Bambara, a language spoken in Mali. We see her teaching a class on Japanese phonology and learn that she's writing a paper to present at the East Asian Linguistics conference. She seems pretty good at identifying regional and foreign dialects and accents, and in fact uses that to help solve the murder. She pops up with a smattering of greetings in languages like Russian and Greek.
But what is linguistics? It's a wide-ranging field with a number of sub-specialties. You can read about it here: http://en.wikipedia.org/wiki/Linguistics.
You don't have to know a bunch of languages to be a linguist, although many do. You could spend all your time theorizing about the underlying structure of language, or you could go out with a recorder to collect data about a language that has only two speakers left who learned it as their first language. You could trace back the history of words like 'apron', which was misanalyzed after it came into English from French . When people said, 'a napron' others heard it as 'an apron' and that's what stuck. Or you could track sound shifts that resulted a common Indo-European root for 'father' ending up beginning with a [p] sound in the Latinate languages and an [f] sound in the Germanic languages, of which English is one.
You could measure how many milliseconds an average vowel is in English when it precedes a voiced consonant like [d], [b], or [g] as opposed to when it precedes a voiceless consonant like [t], [p], or [k], and conversely the length of those consonants.
You could study psycholinguistics, sociolinguistics, or typology of languages: is their basic word order Subject-Verb-Object, which the majority of languages use, or SOV, as in English, or VSO. You could study languages that use tone to mark meaning and grammatical function, like Hausa, Yoruba, and Chinese. Linguists also work in forensics, testifying in court about, for example, whether a written confession or a text message was in fact created by the accused.
Speaking of Murder only touches on the possibilities of a linguist as an amateur sleuth. We're looking forward to seeing how else Lauren might use her skills to solve crimes in the future. One of my favorite blogs is linked to on this site: LanguageLog.com. The bloggers are a number of well-known academic linguists who post about all kinds of topics of general interest. I recommend it.
What experiences do you have with linguistics? Any questions you've been dying to ask?