She’s worked late tonight and taken a cab straight from the labs to La Luna, the Chelsea wine bar where she now sits, wondering why she rushed. Martha is never on time. At least tonight, Lucy’s come prepared with the current issue of Biology Today, which she has open to an article on the mating habits of swallows. The magazine lies on the stainless steel bar in front of her and Lucy holds a pen poised to take notes in the margin. Only she’s not really reading, just trying to look occupied to avoid unwanted conversation. Her blond hair is pulled back neatly and folded over in a large barrette, and she wears the thick, black-rimmed glasses of someone who wants to be taken seriously. But even at thirty-three, with a teaching position at Columbia University and the promise of a remarkable career, Lucy can’t quite pull off the look of a seasoned biologist. When she tries, it has the opposite effect, making her seem young and even more approachable, the way a little girl never looks more like a little girl than when she’s dressed up in her mother’s high heels and party gown.It’s a quarter after nine, fifteen minutes past the time she and Martha agreed to meet, which means Martha still has five minutes before either of them considers her officially late.