Well Volunteered
The Modron army leads us onwards, until we find the device that they were after. It's a demon-neutralising device, or something like that, and it just so happens that various demon lords are wandering around the Underdark at the moment, and one is with the device in the cavern ahead. It's convenient, but still not very appealing.
'Maybe we should talk to it', says Krunch. 'And that would require someone who can speak their language of Infernal, which would be you, Charmandrathrax.'
'I agree, and thanks for volunteering me, but I think you mean Abyssal. Which you speak.'
'I—oh balls, so I do.'
'Great, so we're sending in the Barbarian to negotiate. When do you want our initiative rolls?'