The only book of Stevenson's written in collaboration with his wife, to whose powers of invention and descriptive writing the greater part of it is due. It had its origin at the time of his slow and perilous recovery from the nearly fatal illness at Hyeres in the spring of 1884. Forbidden to speak and under orders to lie in darkness, the long hours were relieved by tales which Mrs. Stevenson made up for his amusement. A few months afterwards, when they had settled at Bournemouth, where Louis was to live the life of a delicate girl, these stories were drawn upon as material for a series planned on the lines of the New Arabian Nights of six years before. Though the form is broadly the same — a set of interdependent narratives over which the long arm of coincidence was never more widely waved — the style is notably different from that of the previous series. This is explained by the fact that only the prologue and epilogue and the tale of “The Explosive Bomb” are Stevenson's own writing. All the rest of the book was the invention, and the actual writing of Mrs. Stevenson ; her husband's share in it consisting apparently in revisions and touches by which he was able with great facility to impress a large measure of his own style upon his wife's work.