Book of plays (4)
I believe the answer is:
acts
This clue is a double definition.
'book' is the first definition.
(book of the Bible)
'plays' is the second definition.
(I know this)
'of' is the link.
(Other definitions for acts that I've seen before include "Book; play parts" , "Cast (anag) - performs" , "Legal documents" , "5th NT book" , "Turns" .)