Why did we travel to New Ulm? You were summoned by the king.
The king has summoned me. Who is he? I mean, if I'm just traveling through and the king summons me, why should I obey? He's not my king. As a warden, you are a basically a peacekeeper of the kingdom. He is your king.
The note about Wardens suggests there's more back story that I'm not aware of. Wardens are tasked with protecting the kingdom. And there was a previous quest line where the players became wardens.
I'm not sure part of this makes sense: a powerful dwarven king has allied himself with an army of elves. The two of them have declared war on a human king. Now the king wants our small group to defeat two entire armies? Where is the king's army? If he doesn't have one, why isn't the war already over? Is this just a tiny part of the war? Is our group asking for peace? Why would we confront both of them? The king's guard is lead by the dwarven warrior. He is using the king's army against him. Getting the Lady's help is the only way to secure an army. Full out war hasn't started, by it's mainly the wardens own soldiers keeping the enemy at bay. You only need to confront the dwarf if he is present or they choose to seek him out.
If the Lady is suspected to be under a spell, is the king sending one of his wizards with us to help remove the spell? What are we supposed to do when we meet them? Are we assassins?
The group is composed of a female sorcerer half-elf, a male half-orc rogue, a male orc barbarian, and a female human paladin. They have the option to try sorcery on her, they have an assassin through the rouge, they have brute strength for confrontation. It depends on how they want the problem solved.