Simplify the following text for a Grade 5 native English-speaking person.
Original: They all go to visit Lyme Regis , where Wentworth 's friend Captain Harville is staying . Captain Harville had been mourning for his sister , who died young , and comforting Captain Benwick , who had been engaged to marry her .
Simplified: Captain Harville -- A friend of Captain Wentworth .