Yoo Si-jin to pull on Kang Mo-yeon's heartstrings in 'Descendants of the Sun'

Yoo Si-jin, played by Song Joong-ki, will continue to tug at Kang Mo-yeon's heartstrings in "Descendants of the Sun" next week, as contact between the couple is cut off during a post-earthquake rescue operation.

In the most recent episode on Thursday, doctor Kang (played by Song Hye-kyo) tells Army Capt. Yoo over the phone to apologize for kissing her without permission. Yoo obliges, bids her farewell and leaves for South Korea from the fictitious war-torn country of Uruk.

In South Korea, Yoo continues business as usual until he hears that Uruk has been struck with a high-magnitude earthquake. He takes the next flight back to Uruk to reunite with Kang and has this to say, "I've regretted it all along -- not seeing you before leaving that morning," he tells her as he ties her shoelaces. "I can't be beside you so please look after yourself."

The show cruised to a 28.5 percent viewership nationwide on Thursday, past the 28.1 percent high recorded by "My Love from the Star," a benchmark for Korean dramas.

In the sixth episode of "Descendants of the Sun" next Wednesday, a power plant collapses after an aftershock, with Yoo and his colleague Seo Dae-young (Jin Goo) participating in a rescue operation. But a walkie-talkie communication between the two and the staff above gets lost, sending Kang and Seo's love interest Yun Myeong-ju (Kim Ji-won) into a panic.

"Descendants of the Sun" airs Wednesday and Thursday nights at 10 p.m. (Yonhap)