Apportionment of Blame

When Joyce Hetherington loses her half-sister in a mysterious railway accident, she calls on her old school friend, Greg Mason, to investigate. As the two sink deeper and deeper into the case, they begin to realise that certain seemingly unrelated threads in her family story ? some stretching as far back as WWII ? have the potential to weave a web with far greater implications than either of them could have ever imagined.