Probably 3.5 rounded up.

It's really a gripping story - its an interesting blend of truth and fiction. I love that Kate focuses historical fiction on womens work in the war.

but this one was also just a BIT too long - there is so much time spent building up the end that at times I just felt like saying "yes all this is the same get on with it"

However I was still engaged until the end trying to figure out what was going on and who I could believe and trust throughout.