Are you who you say you are?

Having been well and truly pulled into the tension and drama of A Murder is Announced by Agatha Christie, I am trying to work out who might not be all that they seem.

A comment that is made in the novel is that before the war (WW1) villages were full of people who all new each other and newcomers had to prove who they were. But now villages are made up of people who have come from all over the country and there is very little that can be done to prove that you are not who you say you are. So an easy time to steal an identity.

Looking forward to working out who is lying about their identity.