Simplify the following text for a Grade 9 native English-speaking person.
Original: No Mercy ( 2007 ) was a professional wrestling pay-per-view ( PPV ) event produced by World Wrestling Entertainment ( WWE ) , which took place on October 7 , 2007 at the Allstate Arena in Rosemont , Illinois .
Simplified: No Mercy 2007 was a professional wrestling event available on pay-per-view made by World Wrestling Entertainment ( WWE ) . It was the ninth yearly No Mercy event and took place on October 7 2007 at the Allstate Arena in Rosemont , Illinois .