This is a collection of short stories written for the Weird Tales magazine which Robert E. Howard inventor of Conan and Soloman Kane also wrote for, although they are different in style from those tales, less fantastic adventure tale and more like the cosmic horror genre of HP Lovecraft and Clark Ashton Smith (although not as good as Smith, at least not consistently so).
The book is divided into two parts, the first part is the smaller and features Jirel of Joiry, a kind of medieval warrior princess who made me think of a cross between Bodica and Joan of Arc and the second part, the greater part of the book, feature Northwest Smith, a space adventurer/smuggler who reminded me of some kind of a cross between Indiana Jones and Han Solo (of the early unscrupulous space pirate Greedo shooting variety).
In many of the stories, both the Jirel and Smith ones, the theme is one of the protagonists stumbling upon or having to enter alternative worlds and this is where the cosmic horror angle plays out. Jirel crosses through a wizard's magical doorway into a world dominated by a sorceress and in two other adventures uses a strange passage (which made me think of tunnel made by a giant worm or something like it) to venture into a demonic otherworld which is described as hell. Northwest Smith while hiding from the authorities stumbles upon an alternative world dominated by a carnivorous tree when chasing someone through a shadow, in another tale he falls asleep and is drawn into a similarly weird landscape in which anyone can be prey to an unseen predator and death at any time by a shawl or blanket he bought which was a relic, in still another by being party to hearing a story related in magical language he is transported through time and space and confronts God like entities.
Additional to the recurrent theme of alternative or other worlds which the protagonists have to quest into or accidentially stumble upon there are themes of struggle, endevour or endurance and will, Jirel has to match her human will with that of demons, a malevolent darkness which could be the devil itself and a sorceress, while Northwest Smith tangles with alien life forms, quasi-deified monsters and forgotten Gods. More than once the adversaries are vampiric, seeking to drain away life force and those that dont want to surmount the protagonists will and dominate them, in both Jirel and Smith's tales what makes for a hero is an insurmountable will and unconquerable character (although in at least two of Smith's tale's he is overwhelmed and lucky to have others come to his aid).
Some of the stories are much, much weaker than others, ramble a bit or are uninteresting for the most part but almost all of them have some excellent pages or passages which make reading worthwhile.