Run off to get a latch (4)
I believe the answer is:
bolt
This clue is a double definition.
'run off' is the first definition.
(I know that run off can be written as bolt)
'a latch' is the second definition.
(I've seen this before)
'to get' is the link.
(Other definitions for bolt that I've seen before include "Rush away - fastening bar" , "A . . . . from the blue is a complete surprise" , "writer" , "Run away; bar of lock" , "playwright" .)