How the ghost appeared at the stroke of midnight? (4,2,4)
I believe the answer is:
dead on time
'how the ghost appeared' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'at the stroke of midnight?' is the wordplay.
'at' says to put letters next to each other.
'the stroke of' becomes 'deadon' (I can't justify this - if you can you should give a lot more credence to this answer).
'midnight?' becomes 'time' (midnight is a kind of time).
'deadon'+'time' is 'DEAD ON TIME'.
Can you help me to learn more?
(Another definition for dead on time that I've seen is " Punctual".)