Rapid aging afflicts all six colonists on Gamma Hydra IV and five members of Kirk's six-man landing party - all but Chekov. With the Neutral Zone so close, suspicion falls on the Romulans testing a new weapon, but is it? With time running out, answers are elusive. As Kirk's memory progressively deteriorates, regulations necessitate a competency hearing no one wants - the outcome of which may eventually lead the Enterprise to its destruction with all aboard. Written by
Did You Know?
resisted looking too old as Captain Kirk aged. This is why at first the aging Kirk's hairline is receding but later his hair is fuller. See more
In the final shot, Chekov is suddenly wearing a wig instead of his natural hair. (The shot was obviously borrowed from an earlier episode.) See more
I don't know what's causing it. Virus, bacteria or evil spirits, but I'm trying to find out.