Journey to the Ygg
Journey to the Ygg is a one-shot idea for winter. It is planned for 4-6 adventurers of 8th level.
Plothook
In the land of Arctus, each year a pilgrimage is made to The Ygg, the great tree. Without the ceremony and offering, the Tree's roots weaken, allowing greater monstrosities to escape the caverns beneath. You were chosen for your strength, skill, and cunning, to guard the caravan to The Ygg. During the last cycle, the caravan failed, and hard times have come since. No one is sure what happened to the last caravan, but none returned. Many crops failed, game has been scarce, and this winter is looking colder than the years before.
But hard ground makes for stronger roots.
Your mission is, through stealth or strength, to ensure the priest makes it to The Ygg and completes the ceremony. The priest, Erelyn, has seen many cycles. He was retired, with a successor taking the mantle. But with the last year's failure, he has returned from retirement to make the pilgrimage once again.
Enemies
Hydra (final encounter)
Death Dogs
Displacer Beasts
Deep Crow (not meant to be fought, plot device to push them underground)
Young Kruthik
Adult Kruthik
Kruthik Hive Lord
Story Beats
Set off from town
Erelyn giving more information as they travel, as he is experienced.
Confrontation with Death Dogs
A deer runs across the trail. Unnervingly, the deer's thigh sloughs off and falls to the ground in the middle of the road. The deer stumbles and falls, as a wolf pounces on it. A head turns towards the party as the other eats the discarded flesh.
A successful nature or survival check (DC 10) identifies it as a Death Dog. DC12 they are informed of the nature of the diseased bite. DC15 recalls they are afraid of fire, and won't attack anyone holding a torch or other flame. Ranger with Monstrosity focus automatically identifies them and has advantage on the latter 2.
As one head has the group in it's sights, the other howls.
In 2 rounds reinforcements arrive. 2 on round 3, 1 more on round 4, and 3 on round 6.
Death from above
As dusk settles, you hear an echoing "caw" in the distance... Nature or survival DC15 identifies that as a Deep Crow, only heard of in stories. Erelyn recommends getting underground immedietly. Conveniently, there is a 10x10 cave entrance nearby.
The party can make camp at the mouth of the cave for a long rest and continue overland in the morning, or proceed through the caves (see 3.5), before or after a rest.
...and below
As they journey deeper into the caves