Korea's first nuclear submarine and a crew with no record of existence embark on a do-or-die mission into the deep waters of the Pacific.
| Actor | Role |
|---|---|
 Choi Min-soo202 / Executive Officer | 202 / Executive Officer |
 Jung Woo-sung431 / Lee Chan-seok | 431 / Lee Chan-seok |
 Yun Ju-sang000 / Captain | 000 / Captain |
 Son Byung-ho562 | 562 |
 Go Dong-eop561 | 561 |
 Kim Young-ho872 | 872 |
 Sul Kyung-gu432 | 432 |
 Jung Eun-pyo981 | 981 |
 Park Gil-su841 | 841 |
 Park Ho-san434 | 434 |
 Min Bok-gi982 | 982 |
| WWoo Seung-yeup842 | 842 |
 Oh Sang-moo532 | 532 |
 Lee Cheol-min531 | 531 |
| HHan Young-su496 | 496 |
 Lee Hwang-eui498 | 498 |
 Lee Yang-hee771 | 771 |
| KKim Yong-sooChan-seok's father | Chan-seok's father |
 Park Choong-seonLee Tae-jun | Lee Tae-jun |