This is going to be a winner with my Year 6s, huge fans of this series. This is Horrible History at its best with all the horrible facts conveyed by a pacy gripping narrative. Topher and Ka his time travelling cat find themeslves in London in 1858, the year the river Thames came to a standstill because it was so full of sewage. The smell drove MPs from the Houses of Parliament and urged on by Queen Victoria herself, the PM decided at last that Something Must Be Done. Enter Joseph Bazalgette, engineer extraordinaire, who built the sewers that transformed London. But Bazalgette had enemies, not least the owners of the big houses that had to be destoyed to build his system. The plot centres on an attempt to murder Bazalgette, discovered by our hero and his cat. A largely unsung hero this book should do something to make Bazalgette as well known as he deserves. Florence Nightingale also makes an appearance though as one of the many who resisted the engineer's claim that sewage was causing the cholera epidemics that swept through the city. An excellent informative fast moving thriller.