Unstable, upper-class, suicidal emperor’s story (1,8)
I believe the answer is:
i claudius
'emperor's story' is the definition.
(novel about the Roman emperor Claudius)
'unstable upper-class suicidal' is the wordplay.
'unstable' indicates anagramming the letters.
'upper-class' becomes 'u' (similar in meaning).
'u'+'suicidal'='usuicidal'
'usuicidal' anagrammed gives 'I CLAUDIUS'.
(Other definitions for i claudius that I've seen before include "Graves 7 novel" , "Historical novel by Robert Graves" , "Drama" , "TV series" , "Work" .)