While screwing home the faceplate screws on a ringmain twin socket
outlet after easing them for painting, I had a 'flash-bang' moment,
for one of the screws had trapped - then penetrated - the live cable.
Doh! After I'd isolated the whole shooting-match and replaced the
fuse, I discovered that the spur socket, fed from the original
ringmain socket, was dead. So I disconnected the spur cable
completely, isolating the ends properly.

Now I want to identify the point of breach of the ~6 metre spur
circuit cable, and repair it. However I do this, there will be some
plaster to cut away, somewhere, and make good. This, I want to
minimise.

I have a Newlec multimeter and simplistic instructions
( appropriate! ), and expect I'm going to do a 'Continuity test' at
intervals along the cable, but I'm uncertain about what I'm looking to
see, to identify the point of breach.

Can someone kindly advise?