Season 1

While on vacation after a sensitive military operation, soldier Si-jin senses a connection with Mo-yeon, a beautiful and strong-willed surgeon.

Si-jin and Dae-young engage in a perilous operation in Afghanistan, while Mo-yeon assists in surgery. Later, Si-jin and Mo-yeon take in a movie.

Si-jin and Alpha Team join Mo-yeon and the doctors in Urk. Meanwhile, Myung-ju doesn't like how her father, Lt. Gen. Yoon, treats Dae-young.

Tempers flare over a dying man when Mo-yeon insists she can save the patient's life. Meanwhile, Dae-young and Myung-ju reunite at the airport.

After sharing a moment, Mo-yeon isn't sure what to think about her relationship with Si-jin. Later, Si-jin receives a panicked phone call.

In the earthquake's aftermath, heartbreaking decisions must be made by Si-jin and Mo-yeon, who both strive to save as many people as possible.

When an aftershock strikes, Mo-yeon sees firsthand just how dangerous Si-jin's job can be. Later, an old phone message is accidentally broadcast.

Dae-young is rattled after seeing an old nemesis, Mo-yeon shares a dark dinner with Si-jin, and an unusual package arrives from home.

While Dae-young and Myung-ju remain quarantined, the rest of the team fights the epidemic. Meanwhile, the supply truck with the cure disappears.

Dae-young has a bad feeling about Si-jin's solo mission into Agus's hideout. Mo-yeon wonders if she's capable of dealing with Si-jin's secrecy.

The medical team returns to their regular lives, but something's off. Meanwhile, Mo-yeon makes a bold career move, and Dae-young faces a tough choice.

After a patient is rushed to the hospital, Mo-yeon is shocked to see who is in need of care. Meanwhile, a microchip reveals unexpected information.

Si-jin and Mo-yeon spend some much deserved time together. Dae-young and Myung-ju continue to have communication problems. Devastating news arrives.

Mo-yeon and Myung-ju learn that not everything is what it seems. Meanwhile, a promotion is cause for celebration, and a trip reignites old passions.