Lucy Liu on directing zebras for "Elementary"

In Thursday night's episode of the CBS drama "Elementary," Lucy Liu's character takes a break from work after her boyfriend is poisoned to death. Liu, on the other hand, was working twice as hard, acting in and directing the episode. It's her second directing credit for the show.

"I really love it. I think it's just a natural progression from where I started over 20 years ago," Liu said. "It's funny because you learn from the people you work with around you - not just the crew and directors, but just as a whole you see how everything starts working."

"Elementary" is a modern version of Sir Arthur Conan Doyle's "Sherlock Holmes." Liu plays Sherlock's investigative partner, Joan Watson.

While she's known for her acting, Liu is no stranger to the director's chair. In 2010, she made her film directorial debut with the screen adaptation of the novel "Half the Sky." She directed her first episode of "Elementary" last year.

"The second time around I learned a lot more than the first time," Liu said. "The first time around almost was easier, even though I knew a little bit less, because the script was more narrative and this script was a little more procedural."

The episode also called for zebras -- a problem because shooting took place in the winter.

"At one point we discussed maybe painting little ponies black and white, which we have done before," Liu said. "Trust me, we went through every possible list of things that we needed to do."

Lucy Liu on directing an episode of "Elementary"

Luckily for her, directing the actors proved easier, even though she had to go back and forth between performing on set and watching from behind the scenes.

"I think because I'm so intimate with the cast and they're so comfortable with me it makes it easier in some ways," Liu said.

On the show, the two characters known for their close relationship are Holmes and Watson. While Liu said fans have been wondering how far their togetherness will go, Liu said they shouldn't expect sex.

"We want to stay true to something that's in the literature, which is that they had a partnership, they had a friendship," she said. "Even though it's a modern-day twist, we don't want to end up mixing that too much. Plus the fans area already getting used to the fact that a woman [is] playing Watson."