They are evil ?
If they have commited evil acts, local guards/lord/paladin group want to capture/kill them

Contact them and set up an ambush with them
During the ambush, one enemy spellcaster cast a charm spell on you (give them a scroll of domination)
DM ask to roll save behind screen.
Then you act like dominated and strike back at party

You + the guards/lord/paladin can take down at least some of the party members

And if party succeed, you can continue with them because they will think you were charmed and try again later