"Horrifying act" refers to an action or behavior that is very frightening, shocking, or disturbing. It is something that causes extreme fear, disgust, or horror. Full definition
On page after page, he read testimony about people who performed horrifying acts for the sake of power, money or simply to get along in a country suddenly steeped in the wicked. (discovermagazine.com)
Secondly, the most horrifying act of mass murder or genocide ever perpetrated by humans occurred within a leading Christian nation; and this grew out of an anti-Semitism long present within Christendom. (religion-online.org)
As horrifying acts begin to unfold the criminals soon realize that all is not as it seems in the house, and when strangers from the local town show up the tables are turned, and everyone realizes that death may be the only escape from The House Of The Witchdoctor. (du-hd.com)