Don't know what you mean by 'lever by mouse'.

The talking plate (actually there is 2 of those in Broken Valley) needs a password which you will recieve if you find four scrolls around Broken Valley, that you can get the 'almost wise' goblin near Maxos temple to translate.

"Look at you, hacker. A pathetic creature of meat and bone. Panting and sweating as you run through my corridors. How can you challenge a perfect immortal machine?"