Seeking some E6 adventure ideas for the PCs traveling with dwarven royalty

[yeti1069]

Background:

Spoiler:

The PCs (level 6) departed from the city in which they had met and performed acts of valor in pursuit of a kobold army, thinking they may be led by a dragon. Eventually, they reached the dragon, but were joined on the way by a team of dwarves who had been told of the players' intentions and set out to aid them. Together, they defeated the dragon.

The leader of the dwarven band is Prince Qhildir, son of the king of the neighboring dwarven kingdon, leader of an elite combat squad. He's a paladin, and is a member of a religious sub-sect devoted to repelling evil, generally, and undead specifically, that one of my PCs also belongs to. He also is wearing the armor made from the father of the dragon they all just killed, and wielding the weapon that slayed him hundreds of years ago.

Several of the members of the dwarven strike force perished in the confrontation with the dragon and his kobold minions.

What I'd like is an adventure that does the following:
-gives the players a chance (and some reasons) to grow attached to the prince, to get to know him, and form a bond
-gives the players a chance to explore some of the dwarven kingdom
-involves some social encounters, and some combat encounters that the prince will join them for

The ultimate goal are for the players to spend some time (a couple of weeks to a month) living and adventuring with the dwarves, and to develop an affinity for them, so that, later, when some problems begin to arise in the dwarven capital, the players will have a genuine interest in wishing to aid their friend.

This can include meeting some interesting NPCs, getting into some tough scrapes (combat, traps, environmental hazards, weather, political intrigue) with the prince and a number of dwarven NPCs (the latter won't be traveling with them).

Regional details:

Spoiler:

The dwarven kingdom of Ferrumgaard lies within and around a maintain range to the north of the land the PCs have adventured within. The two kingdoms are on friendly terms after declaring a truce to a war between them waged a few hundred years ago. Dwarves have established settlements of various sizes in the high plains and foothills before the mountains, consisting mostly of low stone buildings with multiple basement levels, while the region's major cities are carved out within the mountains themselves.

There is a trade center at the head of a river that eventually runs by the capital of the southern kingdom, and the major trading port city the players are familiar with. The place exists as a market to sell and trade the goods the dwarves fashion (jewelry, metal- and stonecraft, including both mithral and adamantine items, all of both mundane and magical varieties) and to purchase wares of the varieties that they do not produce (wood, cloth, fur, parchment, etc...). Dwarven farmers also use this as a place to distribute their crops and meats. The entrance lies two days from a small seaport.

Traveling to the seat of the king involves going by foot, or something between a mine cart and a locomotive, from the market city to the capital. Both cities are multi-leveled.

The kingdom is lawfully inclined, and just on the good sign of neutral. The king is a lawful neutral cleric and the society is based largely upon merit, but has a touch of socialism--there are no beggars or homeless, but there are definite gradients in wealth and influence.

On the other side of the mountains are nigh-endless frozen plains...a dangerous place, but somewhere that some dwarves have settled in small numbers. Somewhat to the west, there is a small trollish nation that has largely remained aloof from the goings-on of the dwarves, but has started to expand recently. There may be any number of savage races in or around the mountains (mostly either high up among the peaks, or off to the west) away from the major settlements of the area. Drow may exist somewhere underground nearby.

I'd appreciate any suggestions you may have. Thanks in advance!