Complex sentence: Ray and Polly Cutler (Max Showalter and Jean Peters) go on a delayed honeymoon to Niagara Falls, only find out that their reserved cabin occupied by another couple, George and Rose Loomis (Joseph Cotten and Marilyn Monroe).
Split into simpler sentences: Ray and Polly Cutler (Max Showalter and Jean Peters) go on a delayed honeymoon to Niagara Falls. However, they find out that their reserved cabin is occupied by another couple, George and Rose Loomis (Joseph Cotten and Marilyn Monroe).