Okay, speaking vaguely and hypothetically, this other company is just publishing the books without any arrangement with the author? That has me scratching my head a little. Unless we're talking some ancient book that's fallen into public domain, I'm not sure I'd do that.
True story: there was an old book from the seventies I wanted to reprint a few years back. But, despite repeated efforts, I could not track down the original author or his estate . . . and the original publisher had long since lost track of any records concerning the book.
Eventually, I gave up.
I'm no lawyer, but I wouldn't be comfortable reprinting a book or series that I didn't have the rights to.
I hear ya; it sounds like what happened with me.
I believe the law says something about 50 or 90 years (?) after the author has passed away does a book go into the public domain; because if anyone were to get 'the rights' that company would obviously be in trouble...or at least get a cease and desist.
(I know this question was a bit obvious, but I just wanted to put it out there to get an opinion. Tks).