An investigation is launched when the body of a Marine due to ship out to Korea in the 1950s is discovered.
There really isn't much of a sense of mystery or twist to the screenplay in this installment, it plays as fairly predictable in its setting and outcome. I do like the sense of time, the elements of romance under the circumstances, and the Marine/Navy rivalries that are brought out.
On the other hand, I think that the drill instructor's character has un-needed detail, and it might have been more intriguing and tragic if he went on to a distinguished career. I also think the mixing of black and white and color is a cheap effect here that adds nothing to the story other than "black and white" means "old". Since "Cold Case" has lots of episodes that don't use black and white, it just seems to set off the flashbacks in this episode as "old enough" without adding any sense of a point to be made.
I also would like this series to once or twice devote a few more minutes to the characterizations before the climax and skip the last five minutes of "music and meaningful looks" between the past and present protagonists.