“There’s only one thing we want you to do.”
When you hear that don’t respond. Walk away. Don’t ask. They want you to ask. When you ask, they have you where they want you.
Whatever they offered in exchange for that ‘one thing they want you to do’ is something that they know in advance goes against your grain.
If you just ask out of curiosity what that one thing is, they win.
That same offer will then be off the table, because it was never on it. It was a lie told to manipulate you into a corner so they could take from you more than they were willing to fairly compensate.