SEE ALSO: Dive into the heart of Korean culture with study abroad in Seoul with these 2 Summer Camp programs

Actors Joo Sang Wook and Yang Dong Geun will be appearing on next week's 'Running Man'!

Locked into mysterious helmets which they can't get out of, the 'Running Man' cast and guests must endure a series of challenges -- and is that the sound of ringing bells we hear?

Check out the preview below!