The team heads out to Smalltown, USA to investigate a short string of puzzling deaths. Rachel comes to the forefront, as both prime investigator and damsel-in-distress when she is targeted by an unhinged killer who literally uses love -- or the lack of it, as reflected in biochemistry -- to kill for revenge.
Even with this being a "Rachel" episode, we don't learn much about her. She's sentimental. She doesn't like how germs look. Not much meat there. We learned more about her in a few quick telephone conversations with her mother than we did here.
The actual murder plot is less than riveting. Picking out the killer wasn't challenging, and the plot just went from A to B. Not a whole lot to keep you on the seat's edge.
On the bright side, the show continues to do well with characters. They're drawn well, and, in spite of their abilities, feel like real people, with real motives and real problems. They're fleshing out well. The dialogue and acting continue to be good ... astonishing, coming from a network that brings us entertainment with titles like "Velocigator vs. Mega-Shark-Tron".