The Cocky Cavalier and the Mad Wizard
A cavalry officer, Colonel Garrald, wants to retake Maquosmouth with a company of elite horsemen. His confidence is based on the claims of Zumthar the Erudite, a mage who reckons he can close the Chaos Portal. The PCs are invited along for the ride by a friend who is accompanying the mage and colonel.
The cavalry company fight their way into the northern half of Maquosmouth towards the Chaos Portal. Unfortunately, if they make it that far, they find the mage is low level (6th level) and is quite delusional, believing he has mystic powers that simply don't exist. The Chaos Portal cannot be closed.
Colonel Garrald is over-confident, and not tactically astute - his ideas of command involve shouting louder than everyone else, and the order is nearly always "Charge!" regardless of enemy numbers or terrain.
It becomes apparent that the best hope for the human invaders is to get over the river onto the south bank and link up with the mages who control the golems and living statues. Of course, the mages will be distinctly unimpressed, and negotiations may be needed to get the help the cavalry needs.
Beneath the Temple of Khazep
It is suggested by a sage in Ironmarket that the PCs should investigate the Fortress of Khazep where the Talloak Forest meets the sea. It is known that before the Summoning, great and powerful magic weapons, staffs and spellbooks were created and stored there. The Temple-Fortress fell by treachery within, as Chaos Cultists had infiltrated the temple. There is now an uneasy truce between the three main chaos cults - Pelepton, Slargor and Storshin. Although most cultists are human, each cult has its own monstrous contingent. It is only once the PCs get there that they realise the magic items they seek are not on the surface, but down in the deep, extensive catacombs that are filled with lethal traps and restless undead.
Normally the clerics of Khazep are uncaring and stand-offish, but if the PCs make a serious effort to clear out some of the Temple, the clerics of Khazep would be willing to make the journey and camp nearby, to provide healing and restorative spells as needed.
A Coup in Ironmarket
A chaotic mage is making a bid to take over Ironmarket. He is using summoned elementals to attack and hopefully kill the members of the town council apart from the Colonel of the Town Watch, whose family he has kidnapped. He has also bribed at least one captain of the town watch. He hopes that by controlling the city watch he will have some sort of legitimacy as the new ruler. Of course, he has his own band of hired thugs in addition. Some of these will be apparent from the start, acting as the mage's bodyguards but others will remain in disguise until they can cause maximum surprise and trouble.