The Elf-stone

In my weekly Heroes of Brackleborn campaign, the player-characters defend their titular home village from a gang of bandits and other creatures that hide in the nearby Gloomy Forest. Their party has now made several forays into the forest and have vanquished the bulk of the bandit gang (although not yet its leadership and a core handful of stalwarts.) 

There are many story hooks motivating the players to go adventuring in the Gloomy Forest, but for Armolas, the party's wood elf ranger, exploring the forest is part of her background mission in the village. 

Centuries ago, the region was known as the Gloaming Forest. It was home to her ancestors before they were suddenly driven out by a powerful evil presence. With the elves gone, the forest succumbed to the corrupt forces, becoming a dark and twisted place (and earning its current name). Armolas was sent to this area by the wood elf queen to keep an eye on human matters and investigate the traces of their people left behind so long ago.

In the course of the party's last foray into the forest, Armolas heard an ethereal sound, like distant tinkling wind chimes, coming from an area deeper in the woods. She took note of it, intending to follow up on the curious sound.

On their current foray, in a completely different part of the forest, she once again hears the tinkling chimes, this time much closer. Upon investigation, the party discovers one of the hidden mysteries of the campaign setting: an elf-stone. There are eight of these standing stones throughout the Gloomy Forest, and they were once used by the ancient inhabitants to travel instantly between locations.

Any elf, half-elf, or fey creature who comes within one mile of an elf-stone might hear it “calling” to them…

• Roll DC 12 Perception check to "hear" (sense) tinkling wind chimes.
• The Perception check is at advantage within a half-mile of the stone.
• An elf automatically senses the stone if they pass through the same hex (within a quarter-mile).

Each menhir is 9-12 ft. tall and 4-5 ft. in diameter near its base, tapering to 2-3 ft. diameter at its tip. The weathered stones are etched with sylvan runes. An area of the stone has been worked smooth and carved with a pattern of diamond-shaped sigils arranged in a teardrop shape--a circle of 6 diamonds around a 7th central diamond, with an 8th diamond forming the point. One of the diamonds also has four points radiating from it, giving the entire sigil eight points. 

The players don't know the function of the stone yet, but they should be able to piece together more clues as they find other stones. Armolas has already realized that she is miles away from where she first heard the chimes, leading her to suspect that the diamonds are multiple stones and that this is a different one than the one she heard previously.

The pattern is, indeed, a map of the other elf-stone locations throughout the forest, so I made the players a handout (above) to illustrate exactly what it looks like. Each of the regular diamonds represents a potential destination, while the diamond with eight points (representing the cardinal and ordinal directions) indicates the current stone's home location--although this might not be apparent to the party until they discover more stones.

If a non-elf touches a destination rune, nothing happens, but if an elf does so, they feel a slight tingle in their fingertips. If anyone (elf or no) touches the home rune, they may "attune" to it by rolling a DC 14 Charisma save...

• Elves and anyone already attuned to another stone have advantage.
• Fail =  The character only feels a slight tingle in their fingertips. They can try again in one month.
  
• Success = The home rune flashes and begins to sparkle softly while the character remains within 30 ft. of it, or whenever they leave and then return to this stone. 
• Note that "attuning" to an elf-stone does not count against the number of Attuned magic items a character can carry.
  

Thereafter, whenever the character comes to another elf-stone and attunes to its home rune, the destination rune of every elf-stone they have visited and attuned to previously also begins to sparkle.

• Any (2) attuned runes in the pattern that are directly adjacent are also now connected by a shimmering silver line.
• When an attuned character touches a stone's home rune and then traces the connecting line to an adjacent destination rune, they conjure a fairy door--a misty archway that appears next to the stone. It remains open for up to (5) rounds, or until the character who opened it steps through. 
• Anyone stepping through is instantly teleported to the destination elf-stone.

The pattern also hides a secret portal. When all eight stones have been attuned by a SINGLE character, the pattern changes dramatically.

• With a flash, the central rune changes from a destination/travel rune to a sigil of a magic eye--the arcane symbol representing Luna--goddess of the moon and of magic.
• If the runes are manipulated to open a fairy door to this spot, the characters will appear inside a temple dedicated to the goddess.
  
• The temple was built by an ancient elf-queen named Elusia. It was hidden on the fey realm in the distant past, in order to protect it from the forest's doom. 
• Many of her realm's treasures are stored within, watched over by powerful guardians.