Simplify the following text for a Grade 10 native English-speaking person.
Original: Children of the Mind ( 1996 ) is the fourth , and currently the last , book of Orson Scott Card 's popular Ender 's Game series , a series of science fiction novels that focus on the character Ender Wiggin .
Simplified: Children of the Mind ( 1996 ) is the fourth book of Orson Scott Card 's popular Ender 's Game series of science fiction novels that focus on the character Ender Wiggin .