Speaking of no-charge books, I found The Solomon Kane Mythos by Robert E. Howard at no cost on iBooks, published by Ozymandias Press. It's 322 pages on my iPhone (which probably means it's about 100 real pages in a book).
I'm about 60 pages in and Kane has pursued Le Loup, the bandit leader from the first story, from France (which I will admit confused me, because I associate Puritans with New England, not France) to Italy to somewhere in Africa. Once we're in Africa, Howard gets kind of racist in his descriptions (unfortunate, but entirely expected) but that's also where the real weirdness starts, with corpses rising and an angry gorilla killing the person who killed its mate.