Returned from the newly discovered underground world, Hereward and Zha-rka decide to lend aid to Bishop Montaine and the Holy Knights of Leudik in driving away the sea dragon that has devastated the city with its attacks. They decide to hire yet another theif, this one named Crum, a halfling who has only recently escaped from captivity in the bandit-town of Thudig. Crum, overhearing the two discuss a “pile of money” in the caves below the city, is eager to join the party. They sell off their magical loot to the wizard Zhegherkin, who runs a magic shop in the city.
Our heroes team up with a previous acquaintance, the knight Carolus Carel, to man a ballista tower in an attempt by the Holy Knights to shoot down the great beast. The dragon attacks and the towers prove largely ineffective. Carolus is flung far away by the dragon and Zha-rka rushes to his aid.
Hereward, throwing caution to the wind, leaps atop the dragon, but drops his armaments in the process. He clambers toward its head, trying to find a way to harm the monster.
Crum, finding his inner leader of men, marshalls the remaining knights, Sir Glanmor and Sir Dwynalt, and manages to use the ballista to seriously wound the dragon with two great bolts.
The beast thrashes in pain and dives under water. Hereward, fearful of the boiling river, jumps into the safest place at hand, the gullet of the beast.
With Hereward vanished and the beast fled, Crum and Zha-rka track it to its lair where they discover it has been building a nest. They arrive just as Hereward escapes, horribly wounded, from the creature’s digestive system. The three just barely escape the beasts rage with their lives.
Crum concocts a plan to use goat carcasses stuffed full of Bloodweed to poison the wounded dragon. Along with Sirs Dwyfnalt and Glanmor, the three sneak back into the lair and leave the deadly food behind. Hereward wakes the beast to get its attention on the way out and nearly brings down the cavern in the process.
Later, returning to see if the plan worked, our heroes are afflicted by their own poison! Crum finds a massive green gem wedged under the now dying dragon’s scales, and decides he must have it. He pries it free as the dragon breathes it’s last and when he refuses to leave without it, Zha-rka and Hereward leave him behind. Nearly drowned, Crum finally shakes off the stones influence and swims to the riverbank, leaving the stone and the bottom of the river and the dragon dead in its lair.
The heroes are lauded as saviors of the city. Crum in particular is dubbed ‘Crum the Dragonslayer’ by the common people of Leudik. All three heroes are awarded with gold and the gratitude of the city’s rulers.