Deep Winter was the A.I. assigned to the survey team on planet Onyx, Zone 67. He took the form of an old man with a snowy cape that blew snowflakes and ice as it "moved." Though it is never specifically mentioned, Deep Winter seems to have replaced Eternal Spring when the "smart" AI "died" in 2537. Deep Winter was a 5th generation "smart" AI, which may possess longer life spans than previous generations of UNSC AI, or a "dumb AI," as it seems he lived from 2537 until 2551, double the number of years a 3rd generation smart AI lives.