The Givenchy Code (2005)

Julie Kenner's novel drops Melanie Prescott, a New York math graduate and dog walker, into a real-life version of the online game she loves: someone has sent her a coded message, she may have been poisoned, and a man has been paid for a mission with her name at the top of the page. With the armed Stryker as protector she chases clues across Manhattan against a clock, and the jacket line reads Cryptography is the new black. (Open Library)

Watches

Hampden watch: Walking down 42nd Street toward Times Square, giddy at having solved the last clue, Melanie holds the gold pocket watch it led her to. She had hoped for a fob with an antidote; instead the watch is silent, its hour hand missing, and when Stryker prises the back off with a pocketknife the gears are intact. The dial reads Hampden Watch Company, the case Oneida, and the back carries faded railroad inspector marks with the dates October 14, 1880 and January 15, 1906, which she writes out in a hotel room as the next puzzle to solve before her time runs out; it reminds her of the pocket watch her grandfather got after forty years with a railroad. The maker is named; the grade is not.

Source text: With Stryker looking over my shoulder, we inspected the watch. The dial said "Hampden Watch Company" and the casing said "Oneida." On the back we saw a faded etching with dates (1880 and 1906!) and railroad inspector marks. (Julie Kenner, The Givenchy Code, scan cataloged as Downtown Press, 2005, p. 159, OCR line-break hyphen closed up; the watch is found on pp. 157 to 158 and puzzled over on pp. 178 to 180; her full name is on p. 10; Internet Archive scan OCR)