I don't think this fight will be in tomorrow's ep - they might save it for the May 25 ep. Season 4 = Book 3, last third, they must stretch the plots to give George Martin time to write Book 6 and Book 7 (and maybe Book 8, Book 9... the story may never end)
Martin has already given the basic outlines of the 6th and 7th books to HBO so they can film and finish the show even if he croaks with the books unfinished. Which given how long the wait between Crows and Dance was, I feel is a distinct possibility.