Complex sentence: Once again, Jack's fortune has come under threat-this time due to a number of legal disputes concerning captured slave ships, and it appears that Sophie will have to sell Ashgrove Cottage to keep the family solvent.
Split into simpler sentences: Once again, Jack's fortune has come under threat--this time due to a number of legal disputes concerning captured slaving-ships. It appears that Sophie will have to sell Ashgrove Cottage to keep the family solvent.