Complex sentence: They visit his time as an employee under Fezziwig who is throwing a Christmas party, Scrooge attending and meeting a young woman named Isabelle (Daisy Duck), whom he falls in love with.
Split into simpler sentences: They visit his time as an employee under Fezziwig. Fezziwig throws a Christmas party, Scrooge attends and meeting a young woman named Isabelle, whom he falls in love with.