If you've wondered exactly what role did Sherlock Holmes play in the war with the Martians, here's your answer. Professor Challenger's on board, too. How did Holmes and Challenger know an invasion was coming? How did they survive the occupation of London? How did they capture an alien invader? What was the reason for the Martian landings, and what was the fatal flaw in the Martian plan for conquest? All these questions, and a few others are answered in this book.
You don't have to be familiar with Wells's novel or the Holmes and Challenger tales (not to mention de Maupassant's Diary of a Madman) to enjoy this book, but the more you know, the more fun you'll have, I think. Originally the several parts of the novel appeared as separate stories in The Magazine of Fantasy and Science Fiction, so this is a fix-up novel, but it's fixed up very well.
I have no idea what Holmesian scholars made of this book when it appeared, but Holmes is certainly not the guy I thought he was. His relationship with Mrs. Hudson is, well, surprising. Almost as surprising as the fact that Holmes quotes Keats and reads de Maupassant in French. It's all in fun, though. Check it out.