Strange case cracked by examination in part of the Pacific (5,3)
I believe the answer is:
coral sea
'part of the pacific' is the definition.
(I know that Coral Sea is part of Pacific Ocean)
'strange case cracked by examination' is the wordplay.
'strange' indicates anagramming the letters.
'cracked by' means one lot of letters goes inside another (inserted letters go into a gap or crack).
'examination' becomes 'oral' (oral is a kind of examination).
'case' with letters rearranged gives 'csea'.
'csea' going around 'oral' is 'CORAL SEA'.
'in' is the link.
(Other definitions for coral sea that I've seen before include "water" , "Part of the Pacific with many islands and reefs" , "Place for sailing" , "drink" .)