Myrvin's Gambit

After the events at La Rochelle, a group of Musketeers including Rudy Rideau , Jean de Loungville , Cadwallon Ap Heilyn and a number of other heroes of the War were treated to a vacation to Gilwern in the Kingdom of Cymru.
  Upon arrival, the Musketeers dispersed to the various taverns seeking rest and pleasure. On one particular evening, a group comprising Boniface Le Fevre, Lucas de Bourdain and a mute named Brom Ironwood were enjoying a meal and drinks at the Spotted Dick, a tavern in Gilwern. As Boniface was telling the group about his exploits in the fighting pits and complaining about his meagre pay from his employer, a loud voice cut across the clamour. "French accents!" the voice exclaimed. "Oh, how it warms my bones to hear these voices of la belle France." Suddenly, a hooded figure emerged from the crowds and put his arms around Boniface and Lucas as he sat between them.
The man introduced himself as Myrvin. A Druid from Brittany who explained that he was standing in for the currently missing Myrddin as Arch-druid of Wales. Myrddin had been missing for months, and had not let the other Druids know he was safe since departing to check on the safety of the Thirteen Treasures of Prydain. The Council of Druids was unwilling to worry the King and the people of Wales, and so they asked whether the Musketeers would lend them a hand.
Slightly unsure of the man's story, and of who he claimed to be, the Musketeers invited him on an evening's drinking to get to know each other and thrash out their terms. Lucas immediately set out his stall and stated he wouldn't work for any less than 30 Brooksyns (Livres). Boniface appeared willing to help from the outset, and Brom was mute, as usual. Though he did scribble some words of agreement with Myrddin on his slate, which the Musketeers more often than not, ignored.
As they continued their negotiations, the group noticed a woman leaving the tavern and heading for the exits. A moment or two passed, with Lucas continuing to insist on payment up-front, when a piercing shriek erupted from the street outside. Myrvin looked up, startled. Boniface asked whether incidents such as this were common in Gilwernia and Myrvin simply stood and darted for the door. Needing to other answer, Boniface and Brom followed. Lucas, still bemoaning his lack of payment joined them a few moments later. Outside, they found the dimly lit and misty streets of Gilwernia washed red with blood. Bodies of peasants and locals littered the street in mangled heaps. Boniface spotted a few dead guardsmen and hoping there were more left alive, began to shout out a battle cry to rally survivors to his position. As he did so, five figured lumbered into view through the mist. They groaned and moaned eerily as they shuffled among the bodies towards the tavern. Their eyes fixed on Myrvin, the Musketeers closed ranks around him and readied for battle. As the creatures approached the party could see they were clearly unliving. Corpses brought to life by some dastardly magic. Boniface and Lucas charged forward to engage and distracted 3 of the foes on each flank. Brom, left as the sole shield between the Druid Myrvin and the enemy braced for the charge of a fourth foe. The body broke into a shambling run as he closed on Brom and swung a rusted longsword clumsily towards him. The mute druid was slow to react, and his evasive move unfortunately placed him squarely in the path of the swinging blade. The blow took him by surprise and he fell to the ground, his right hand immediately gripping his left arm as the sleeve began to turn the crimson shade of blood.
  Boniface duelled masterfully against another two enemies as they swung and shuffled around in the street, but he was unable to land a killing blow. As he fended a strike from one of his attackers, he was left temporarily unbalanced by the move and braced for a strike from his second opponent. He blinked in expectation of the blow but as he opened his eyes seconds later he saw a cudgel parrying the longsword and looked around to see a small troop of town watchmen had rallied to his aid. They fanned out and half-circled Boniface's second foe and fell upon him in a clumsy blaze of fury, tearing the corpse into pieces and crushing the skull to a pulp with their cudgels.
  Lucas meanwhile, was duelling playfully with his undead opponent and almost let out a cry of sheer joy as the battle raged around him. He swung his enormous greatsword about with little abandon. After his enemy's blade came a whisker too close for comfort as they fought, Lucas had had his fill of this particular foe and quickly ended the battle. As he turned to find another foe, he saw Brom invoking some kind of magic. He began stepping forward to intercept the cauldronborn that was approaching Brom but as he did so, the cauldronborn's head shattered and the shambling collection of bones fell to the floor, a cloud of dust erupted as the bones hit the cobbled floor. Brom quickly took out his slate tablet and scrawled a message that read "no brain, can't control."
  As the evening progressed and they left the Spotted Dick and went along to the Slap and Tickle, another local tavern in Gilwernia. As they continued to drink the village dry, Boniface began an evening of singing and dancing, holding up a tankard with his false arm as if it were a sacred relic, and the drunkards of Gilwernia were happy to indulge him. One particular local named Taliesin felt a particularly strong calling from Boniface's Holy Tankard and promised to join the Musketeers on their journey in the morning.
The evening drew to a close with Musketeer and local alike strewn about the tavern. Some lay in puddles of vomit or urine, or both. Myrvin, up early as usual, roused his Musketeer companions, Boniface, Brom and Lucas and made ready their horses and supplies. As the party mounted, the local man Taliesin arrived, riding a donkey and holding a stick as a warrior would a sword. He looked ashen pale. He appeared in a hurry to depart and began to harry the party to ready up and leave the village. With some probing, Lucas discovered the man was keen to put distance between himself and a local 'witch' named Ceridwen, whom he had recently annoyed. The details of which he kept to himself, but the party, laughing, decided to make their way to Abbey Cwm Hir in order to seek the advice of the Council of Druids.
  The party travelled for 3 days to reach the hamlet of Cilmeri. The first night....
the second night...
the third night.....
When they arrived at Cilmeri, the weather turned and the River Irfon became treacherous and swollen. It was on the verge of breaking its banks when the party rode through a clearing on it's eastern side. They reined in their horses near the river and turned at the sound of shambling bones. Lucas looked to the heavens through the rain and sighed. More cauldronborn approached and this time in greater numbers.