Where there's pain for Cinnamon, there may be pleasure for The Big Bang Theory's Raj.
Lost alum Tania Raymond head to the CBS hit on Thursday, Feb. 6 when, during the comedy's Valentine's Day-themed episode, Leonard and Penny "almost kill" Raj's beloved canine companion, Cinnamon, and The Hollywood Reporter has the first look at the actress' debut.
During the episode, titled "The Locomotive Manipulation," Leonard (Johnny Galecki) and Penny (Kaley Cuoco) are charged with caring for Raj's (Kunal Nayyar) dog and have to rush her to the vet after a nearly fatal mishap.
PHOTOS: 'The Big Bang Theory's' Nerdiest Guest Stars
"Everybody winds up spending the night in the vet's office," showrunner Steve Molaro tells THR. "Maybe the vet is a cute young lady and maybe Raj is so worried about his dog that for one night he's not a nervous jackass and he's charming. We'll see what happens from there."
While Raymond's role is set at one episode, Molaro stresses that both Melissa Rauch and Mayim Bialik's Bernadette and Amy, respectively, both started with minor roles before ultimately being promoted to series regulars.
Raj's new romance comes after the Big Bang Theory writers had the character (finally!) overcome his selective mutism after he had his heart broken by former flame Lucy (Kate Micucci). This season, Raj has been testing the dating waters but has yet to find any success.
PHOTOS: Behind the Scenes: 'The Big Bang Theory'
Elsewhere during the Valentine's Day episode, Molaro says Amy and Sheldon (Jim Parsons) will have "an impactful and romantic moment" that he's both nervous and excited about when Sheldon and Amy join Howard (Simon Helberg) and Bernadette on a trip to wine country.
And as for Penny and Leonard, Molaro says their botched marriage proposals will continue.
"If you're a fan of the show and you're keeping track, it's now two-to-one: Leonard has proposed twice, Penny has proposed once," Molaro says. "And the answer has been no both times. I like that there's a scorecard and I don't think we're done proposing."
But before the gang gets to Valentine's Day, there's still the Jan. 30 episode in which Star Wars legends James Earl Jones and Carrie Fisher guest star after Howard, Sheldon, Raj and Leonard are shut out of Comic-Con tickets.
STORY: 'Big Bang Theory': 15 Things You Didn't Know
"Wolowitz, Leonard and Raj decide to buy scalped passes but Sheldon's solution is he's going to create his own comic book convention. He just needs one A-list panelist to make it real and everybody's agents are laughing at him and hanging up. But thanks to Twitter, he knows that James Earl Jones is eating at a sushi restaurant in Studio City and he's going to confront him personally," Molaro previews of "The Convention Conundrum" episode. "Sheldon is trying to get James Earl Jones to appear in his own comic book convention and Carrie Fisher appears in a small but hilarious part in the episode."
As for if Princess Leia's famed gold bikini would make a cameo in the episode, Molaro was mum. "We'll see! I'm not against it, but we haven't figured that out yet," he said.
The Big Bang Theory airs Thursdays at 8 p.m. on CBS. Check out more photos from Raymond's appearance, below.
E-mail: Lesley.Goldberg@THR.com
Twitter: @Snoodit
