Elementary season 3 episode 15
Elementary stars Jonny Lee Miller as detective Sherlock Holmes and Lucy Liu as Dr Joan Watson CBS

Elementary season 3 returns with an all new episode tonight, 19 February at 10pm on CBS.

Episode 15 is titled When Your Number's Up, where Holmes and Watson follow a blood trail into the world of wrongful death compensation, when a serial murderer leaves envelopes of cash on the body of the victims.

Click here to watch episode 15 via live stream online.

Click here to watch online.

The official synopsis reads as follows:

Holmes and Watson follow a blood trail into the world of wrongful death compensation when they investigate a series of murders in which the killer leaves envelopes of cash on the victims. Also, Holmes makes a generous gesture towards Watson as she suffers through the aftermath of a personal crisis. Alicia Witt Guest Stars as Dana Powell, Whose Husband Died In a Plane Crash

Natalie Dormer's voice made a welcome return at the end of episode 14, titled The Female Of The Species. Moriarty (Natalie Dormer) fixes Watson's assassin problem and promises that the game wasn't over. So this raises a question, whether Natalie Dormer is returning to Elementary.

According to a report in Entertainment Weekly: "It's a little too soon to say, but the cat-and-mouse game between Joan and Moriarty is far from over.

"Even after three years, Moriarty isn't sure how she feels about Joan," executive producer Rob Doherty said.

"If you classified the relationship as 'adversarial,' Moriarty would tell you you're being simplistic. There's more to it than that. Joan means a great deal to Sherlock, and that means a great deal to Moriarty, and so Joan is afforded a kind of protection. Moriarty won't allow any harm to come to her—at least until her ultimate agenda with regards to Sherlock comes into focus," Doherty added.

It was earlier teased as well that Natalie Dormer could return to Elementary.

"[It's] effing fanstastic, I love playing Moriarty!" she said during a recent Reddit AMA. "And I love being in New York, I hope very much to return. I'm just lulling Sherlock into a false sense of security."

Dormer first appeared in the final arc of season 1, as her alter-ego Irene Adler. It was not revealed that Irene was actually Jamie Moriarty until the finale, at the end of which, she finds the villain being hauled off to prison.