What is correct about the following statement OFF THERE to the right -somewhere- is a large island' said Whitney. it's rather mystery '?

The statement contains a few grammatical errors and lacks clarity. It seems to convey that Whitney is indicating the location of a large island to the right, describing it as a mystery. However, the phrase "OFF THERE" should be corrected to "over there," and "it's rather mystery" should be rephrased to "it's rather a mystery" for grammatical accuracy.