Look whos just arrived to talk about Dickens? (5,2,3,5)
I believe the answer is:
speak of the devil
'look whos' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'just arrived to talk about dickens?' is the wordplay.
'just arrived' becomes 'the' (I am not sure about this - if you are sure you should believe this answer much more).
'to' means one lot of letters go next to another (I've seen this in other clues).
'talk about' becomes 'speak of' (synonyms).
'dickens?' becomes 'devil' (Dickens is an old name for the Devil).
'the' after 'speakof' is 'speakofthe'.
'speakofthe'+'devil'='SPEAK OF THE DEVIL'
Can you help me to learn more?