Especially when you did nothing wrong. They loved to be in the power position and would do whatever at someone else's expense, using others as a scapegoat. I feel I am stuck in the middle. But, if I tell them the truth - they may think I am bashing my last boss. You are in a delicate position, without doubt.
Most employers recognize that there is conflict from time to time with managers and employees.
With the little amount of information you have given me, I suggest that you be honest but tactful. Explain that you were fired and explain the circumstances in as neutral a manner as you can. Try to salvage as much positive as possible by letting the interviewer know what you have learned from the situation. Being fired from a job is not the black mark that you might have yourself convinced it is. Keep your head up and your confidence high and you will do fine in your interviews.