Complex sentence: The men eventually come to the conclusion that they are long-lost brothers because they are completely unalike; their fiancée writes to say she is now engaged to a Mr Knox, and the curtain falls on general rejoicing.
Split into simpler sentences: The men eventually realize that they are long-lost brothers because they are completely unalike. Their fiancée writes to say she is now engaged to a Mr. Knox, and the curtain falls on general rejoicing.