Leak from spy episode (7)
I believe the answer is:
seepage
'leak' is the definition.
(I've seen this before)
'spy episode' is the wordplay.
'spy' becomes 'see' (spy can mean to watch or see).
'episode' becomes 'page' (one part or instalment).
'see'+'page'='SEEPAGE'
'from' is the link.
(Other definitions for seepage that I've seen before include "slow escape" , "running out slowly" , "Oozing liquid" , "Loss from slow leak" , "Percolation" .)