Complex sentence: Adding to Cliff's burdens, Halley leaves for London, where Lester is offering her a producing job; when she returns several months later, Cliff is astounded to discover that she and Lester are engaged.
Split into simpler sentences: Adding to Cliff's burdens, Halley leaves for London, where Lester is offering her a producing job. When she returns several months later, Cliff is astounded to discover that she and Lester are engaged.