Three short novels (well, The Poison Belt is a novella at most) and two short stories of wildly varying quality (but consistently compelling readability: at its worst, this is still Doyle). First up, The Lost World: almost too well known to need a review, this is a thrilling adventure story to which I was first introduced as an infant and have reread several times since, and ensures Doyle's place in the pantheon of science fiction's pioneers (although it arguably owes more to Rider Haggard than to Verne and Wells). It is THE dinosaur story, and let nobody tell you otherwise.
After this rattling yarn comes The Poison Belt, frankly a rather bizarre offering, with very little incident - in filmability stakes, the very reverse of The Lost World; but a clever and well-constructed piece, nonetheless. Make sure you read The Lost World first, and know and love the characters before embarking on the second novel with them.
And then... well, the previous reviewers have already ripped The Land of Mist to shreds, and deservedly so. It begins by stating that the previous novels were fictional but their characters real - the point being that Doyle wishes to dissociate this defence of Spiritualism from his works of science fiction, with which it is in fact unworthy to be classed. Somehow Challenger the radical has become a closed-minded reactionary, representing just the sort of scientists he confounded before; and there are many other inconsistencies. Some are minor (a poison whose name Challenger forgot in The Poison Belt, and cried "Excellent!" on being reminded, now turns out to be connected to a dark secret in his past); others more serious (the Challenger who in The Poison Belt referred to "the Great Gardener" and the "uncertainty" of what happens after death has been transformed into a convinced atheist - although, of course, he becomes a Spiritualist in the end). Two chapters rise above, or at least out of, the mire of Spiritualist propaganda: the one which deals with an exorcism attended by Ed Malone and Lord John Roxton has some of the earlier novels' sense of excitement and adventure; and that dealing with the home life of the fraudulent medium Silas Linden seems to belong in another book altogether. It exists because Doyle trod in Dickens' footsteps as a social reformer, and, indeed, it evokes Dickens' work: but the horrific scenes of child abuse contained therein will turn some readers' stomachs.
From this unwholesome fare we turn to the short stories - light-hearted offerings in the vein of The Lost World, crammed with Doyle's (and Challenger's) trademarks of wit, humour and utterly preposterous science. For these alone the book is worth the cover price (so far as I am aware, they are not available elsewhere, unlike the novels).
It might be wise, unless early twentieth-century Spiritualism and the follies into which even intelligent men could be led by it are an especial study of yours, to skip The Land of Mist; but the rest of this volume would be an ornament to any library.