PLAYING DETECTIVE: Liu (with co-star Jonny Lee Miller) says the mental acumen she exercises on Elementary has made her more astute in real life.
John Paul Filo/CBS

So what can viewers expect in Season 2, which debuts this month? Liu says the season premiere takes place in London and that bits and pieces of Watson’s mysterious backstory will be revealed. “They’re not shy about exposing parts of her family or friends or people she’s dated in the past,” she says, including an ex who developed a drug addiction, a theme that will continue to echo throughout the show as subtext to Sherlock’s life.

“You can’t just use addiction in the premise plot and have it go away,” she says. “A lot of people don’t understand it. It’s not the flu, and you don’t get over it and then two years later get it again. It stays with you all the time. It’s a daily process.”

Doherty says Liu has been an incredible partner in fleshing out the nuances of her character. It was Liu’s idea for Watson to see a therapist, a device that allows for the disclosure of the character’s internal dialogue about her relationship with the complicated Holmes. A few episodes after she proposed it, Watson was on the proverbial couch. Says Doherty: “Lucy sweats the details.”

That includes any involving frocks and hemlines too. The first female Watson couldn’t very well borrow from the black coats and tweeds of her predecessors, so Liu and the show’s costume designer, Rebecca Hofherr, have forged a new sense of style for Watson, dressing her in pieces that are casual and a bit funky but never over the top. “You don’t want her to show up at a crime scene with some sort of crazy outfit,” Liu says. “We do a hodgepodge of everything. We do H&M and Topshop and mix it with Rag & Bone. We’re not an elitist group on the show, for sure.”

Just then, the couple at the table next to us rises to leave but not before introducing themselves to Liu as huge fans. “We just love you,” the young woman gushes, her dark eyes shining with excitement.

“Ah, that’s so nice,” Liu says. “Thank you.”
“I actually auditioned to be your younger­ brother on Joey,” the woman’s lunch partner says, referencing the Matt LeBlanc–led Friends spinoff that Liu made several appearances on.

“That’s too bad, but there will be another opportunity,” Liu tells him, then asks him his name. “OK,” she says. “I’ll look for you.”

The exchange is typical of Liu, a gracious A-lister with a penchant for privacy. She is rarely targeted by tabloids, and her personal life remains much of a mystery. During our interview she often answers questions from Watson’s perspective as a way of deflecting attention from herself. At least, that’s my hypothesis.