Jennifer Sayles is a friend of Joan Watson.
|While shopping at a flea market, Watson and Jennifer discuss Sherlock Holmes and that there is a dearth of cases. Jennifer asks Joan to track down "Tony" a photo journalist she had a one-night stand with. Jennifer believes Tony is "the one" as they had a magical evening together. Joan agrees at Jennifer's insistence. When Watson tells Holmes about the case, he is very unenthusiastic about Watson taking it on and tries to dissuade her from pursuing it. Watson goes to the bar Jen met Tony at in little Brazil and realizes Jen was at the bar on Brazilian Day and that she might be able to find Tony by obtaining local news footage of the party held at the bar.
|Watson brings the news footage back to The Brownstone where Holmes tries to stop her from watching it. Unable to, Holmes admits that he is "Tony" and that he ravaged Jen who he identifies as having a beauty mark on her left torso, size 6 feet and that she bites her nails. Holmes explains that when Watson was his sober companion, he followed her when she went out so that he could learn more about her. After Watson left the Brazilian bar, he approached Jen who he describes as aggressive and limber and that she initiated their sexual encounter.
|Later, Watson meets Jen for lunch and Jen says that Holmes explained everything. Jen expresses her thanks to Watson who realizes that she slept with Holmes again. Initially Jen denies she slept with Holmes but she relents and says she did it because Holmes was so sweet and wanted to ensure that everything was right between her and Watson. She also admits that she came onto Holmes. At the Brownstone, Watson tries to fool Holmes by lying that the reason Jen had sex with him was to have a baby. Holmes doesn't buy the ruse. ("Ancient History")