Lassie in heaven? (3,4)
I believe the answer is:
dog star
'lassie in heaven?' is the definition.
'dog star' can be an answer for 'lassie' (I've seen this before). I'm not sure about the 'in heaven?' bit.
'lassie in heaven?' is the wordplay.
'lassie' becomes 'dog' (I've seen this before).
'in heaven?' becomes 'star' (I can't justify this - if you can you should believe this answer much more).
'dog'+'star'='DOG-STAR'
Can you help me to learn more?
(Other definitions for dog star that I've seen before include "slightly flashy night-spot?" , "clearly visible shiner" , "Lassie, perhaps" , "Sirius in the sky" , "heavenly body?" .)