One's to produce picture internally, for first of stars contracted influenza (11)

'one's' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

'picture internally for first of stars contracted influenza' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found within the answer.
'influenza' could be 'flu' ('flu' can be a synonym of 'influenza') and 'flu' is present in the answer.
This explanation may well be incorrect...

'to produce' is the link.

Can you help me to learn more?