Danbooru 2 theme - prev and next links missing on images?

[l-mcb]

Hi, my friend made a booru. They changed the theme to danbooru2 and it's a really good theme, but I can't find the previous image and next image links on an image's page. I'm the type to overlook obvious things so I'm not sure if it's a bug or if I've just missed them!
They were present on the previous theme (default).
I am using firefox if that makes any difference.
Thanks