Complex sentence: Meanwhile, Michael's psychiatrist, Dr. Sam Loomis (Donald Pleasance), knowing Michael's intentions, follows him to Haddonfield, and meets with Sheriff Leigh Brackett (Charles Cyphers), Annie's father, warning him about the danger Michael poses.
Split into simpler sentences: Meanwhile, Michael's psychiatrist, Dr. Sam Loomis (Donald Pleasance), arrives in Haddonfield. Dr. Loomis meets with Sheriff Leigh Brackett (Charles Cyphers), and warns him about the danger Michael poses.