Complex sentence: Sergeant Howard (Adam Ferrara) instructs Blart to leave the mall immediately, but when Blart unknowingly sees Amy's car in the parking lot, he realizes that Amy is still inside as a hostage, and decides to rescue her and the rest of his friends.
Split into simpler sentences: Sergeant Howard (Adam Ferrara) instructs Blart to leave the mall immediately. However, when Blart unknowingly sees Amy's car in the parking lot, he realizes that Amy is still inside as a hostage and decides to rescue her and the rest of his friends.