In this episode, a soldier has the ability to see who is going to die that day. The gift terrifies him, and he starts to exhibit signs of a nervous breakdown.
At the end of the episode (which you should see for yourself—I'll try to avoid spoilers), Rod Serling's voice comes in and gives a quote from Richard II (which he mistakenly attributes to Richard III): “. . . he is come to open / The purple testament of bleeding war” (Richard II, III.iii.93-94).
Links: The Episode at Wikipedia.