Complex sentence: Worried that she may have done something to Megan while in a drunken blackout, Rachel begins to investigate the disappearance, lying to Megan's husband to get close, and causing distress to both Tom and Anna with her frequent drunkenness.
Split into simpler sentences: Worried that she may have done something to Megan while blacked out and drunk, Rachel begins to investigate the disappearance. She starts lying to Megan's husband to get close to him, and causes distress to both Tom and Anna with her frequent drunkenness.