Book Five of the Case of the Risen Series.
"Things can't get any worse," Challenger said, examining the horrid mess of goo before him.
"Oh, but it can," Holmes replied, stooping to take a sample.
"Much, much worse."
London is facing a contagion that threatens to wipe out its entire population.
Only a handful of men have any idea of what is creating it.
Will they be able to stop it in time?
It's no longer just a threat: it's war!