Novel cover showing nothing but a strange man in dire risk (4,4)

'novel cover' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'nothing but a strange man in dire risk' is the wordplay.
'nothing but' becomes 'o' (I can't explain this - if you can you should give a lot more credence to this answer).
'a strange' indicates anagramming the letters.
'in' is an insertion indicator.
'dire' indicates an anagram.
'man' anagrammed gives 'nma'.
'o'+'nma'='onma'
'risk' anagrammed gives 'irsk'.
'onma' inserted inside 'irsk' is 'IRON MASK'.

'showing' acts as a link.

Can you help me to learn more?