Evermore automatically abbreviates all posts when they appear on a multiple-post page such as the main blog page.
The main page of a blog can often be too full. By default, WordPress displays the last ten posts on the main page, so viewers have to do a lot of scrolling to see if there's something interesting. With Evermore, all posts of the main page are abbreviated down to the first paragraph, so visitors can easily scan your posts, find something interesting, and become hooked.
Include the magic word <!--nevermore--> in any post and Evermore will ignore that post. The magic word won't appear when people view your post, but Evermore will see it and obey.
Just go to your WordPress Admin screen and disable the Evermore plugin. Everything will be back as it was.
You can manually add <!--more--> to all your posts. This has exactly the same effect as Evermore. But with Evermore, you can turn the abbreviations on or off with a few clicks just by enabling or disabling the plugin. With the manual way, you have to go in and edit each individual post.