Simplify the following text for a Grade 12 native English-speaking person.
Original: Each episode ( 156 in the original series ) is a mixture of self-contained drama , fantasy , science fiction , suspense , or horror , often concluding with a macabre or unexpected twist .
Simplified: Each episode ( 156 in the original 1959 TV series ) is a mixture of self-contained drama , fantasy , science fiction , suspense , or horror , often ending with a dark or unexpected twist .