she is simply make a lot of conversations possible in the scene..and find out the actual muderer..
This is a good one .. when concentrated..otherwise a mere junk of people talking and talking and talking..
As Jane Marple sat basking in the Caribbean sunshine she felt mildly disconnected with life. True, the warmth eased her rheumatism, but here in paradise nothing ever happened.
Eventually, her interest was aroused by an old soldier's yarn about a strange coincidence. Influriantingly, just as he was about to shoe her an astonishing photograph, the Major's attention wandered. He never did finish the story....