Bill and Franklin are polar opposites in many senses, but their partnership in the private detective world works well... well, fairly well. Which is not to say that when Franklin is hand an envelope full of cash that they can easily turn it down. And 'down' is a very operative word as Franklin discovers a very worrying truth about what is really going on beneath the streets of London. And when the mismatched pair become embroiled in a whole new Gunpowder Plot, life for the pair of them becomes a real challenge...