"Den of the Rotten Kings" is a wererat lair suitable for four 3rd-level characters. This adventure can be completed in one session.

The party arrives at an abandoned outpost in a frozen landscape. The outpost appears to have suffered some strange attack. A halfmad scholar from a distant city hides in the outpost; he is drawn to the region by his visions of a breach in the ice nearby—a breach he believes leads to the realms beyond the stars. Heading east, the party finds that the breach is no simple chasm in the ice, and its scaled guardian does not appreciate its work being interrupted. In this frozen and otherworldly adventure the party must overcome rimy insects, a void dragon wyrmling, and the pull of the breach itself.

"The Dark Forest" is an elder shadow drake lair suitable for four 8th-level characters. This adventure can be completed in one session. A hidden grove within a dark forest has been home to a tribe of alseids for generations. The tribe's most recent leader and spiritual heart was an alseid shaman called Riatha the Raven. Within the grove lies an ancient ring of standing stones atop a burial mount. Here, Riatha conducted sacred nature rites to honor and bless the forest and the tribe. During one of these ceremonies, the ground rumbled and a column of dense black energy shot straight up from the burial mound and into the night sky. Thick darkness enveloped the area, and the suddenly blinded alseids heard terrible roars. An instant later, the darkness dissipated to reveal a mysterious pool ringed with skulls among the standing stones. Two large, dragon-like creatures with black scales and burning red eyes glared at the confused alseids. One the ground lay the body of Riatha, deathly still. Terror and chaos followed as the creatures brought swift and sudden death, killing most of the alseid tribe members with razor-sharp teeth and deadly, black breath. The alseids that survived the inital, bloody attack fled into the forest. They counterattacked a few hours later, desperate to reclaim their grove and recover the body of their beloved leader, but the attempt was a fiasco and they were quickly driven off. Now, the few remaining alseids hide in the forest, frightened and unsure of what to do next.

History states that Zobeck was reborn in blood 80 years ago, thanks in part to the creation of gearforged by a revolutionary coalition of workers and mages. Unfortunately, history has recorded only part of the truth, and the Praetors will do anything to make sure the rest remains buried.

"Temple of the Deep Ones" is the lair of a group of deep ones and their god, suitable for four or five 7th-level characters. This adventure can be finished in one session. Ship captains report that a mysterious island has surfaced in the middle of a heavily trafficked trade route. Worse, ships that venture too close to the island are assaulted by a terrible creature and its servants. The island is disrupting trade throughout this part of the world, and several ships have already been lost. Unbeknownst to those that know of the place, the island rises at the will of Shar-Ngolyeth, a long-lost deity also known as That Which Lurks Beneath the Waves. The island is populated by a cult of deep ones and the beasts they have subjugated in the name of their dark god. The creature responsible for sinking ships is an aspect of Shar-Ngolyeth, a kraken. It is not meant for combat encounters; it's largely a plot device in this encounter.

Beware the night-things, strangers!

The city is plagued by an affliction being called "stone sickness" or "the gorgon’s touch" that disorients people and turns them to stone. Those with, or suspected to have, the affliction are being banished from the city. Some demand a cure, but most are just scared for their loved ones. A ravenfolk woman named Spinel Larkdon, mother to a child with the gorgon’s touch, begs the PCs for assistance. An artifact known as the Shroud of Tiberesh, capable of curing any sickness, is locked away within The Umbers' vault of spoils below the city. Passionate, she is determined to save her son and all those afflicted. Fortunately for the player characters, completing the Umber’s Gauntlet alive means they are not only entitled entrance into the cult, but also a single item from its vault of spoils. The PC's only hope of procuring the Shroud is by traversing this initiation Gauntlet – a series of traps, monsters, and puzzles devoted to the demon-god Nakresh - and claiming the Shroud as their prize.

Citadel of the Void Dragons is a void dragon lair suitable for four characters of 14th level. It is a logical sequel to Sky Stairs of Beldestan, but it can be played independently. The void dragon Astraxis and his mate, Yrsinestra, have long lived in an orbital citadel where the sky meets the void. This location allows the dragons to communicate with malign creatures of the void and still enables them to feast on the whales, cattle, and other large animals of the firmament below. This ready food supply is urgently needed right now, because the mated pair has recently laid a clutch of eggs. As a result, Astraxis is almost never at the lair—he is constantly on the hunt, bringing food to Yrsinestra and often sleeping on the earth below the citadel.

The trouble began several weeks ago when a duergar excavation team went to work in a long-abandoned temple. Drawn to the temple by stories of riches and artifacts, the duergar hired several giants as laborers before cracking the temple’s sealed doors. The largest of the giants, a loathsome Thursir mutant named Huppo, used his acidic vomit to expedite tunneling into the temple’s collapsed hall of worship. Then, Huppo found the horn—an unusual instrument made from a single piece of stone, with a mouthpiece so intricate only a master carver could have made it. The horn became the giant’s obsession. Seeing only the horn’s potential sale value, the dwarves demanded Huppo turn it over to them, but Huppo refused. To force compliance, the dwarves stopped feeding the gluttonous brute, but Huppo had already found his own source of food; in deep areas of the temple, worms were chewing out of the rocks, and Huppo ate them by the fistful. He also played the horn. Then, after several days of blowing the horn and devouring the strange worms, Huppo released a belch so noxious the dwarves had no choice but to lock him in a sealed chamber and carefully consider their next move. The horn’s call, however, had caught the attention of passing nomadic orcs. They set up camp outside the temple entrance in the hope of finding the horn and its player. That’s the current situation at the temple: the giant refuses to stop blowing the horn and belching out deadly clouds of stomach gas; the dwarves are frightened and edgy while their leader is obsessed with malevolent whispers; orcs are threatening to overrun the place; and the population of worms grows steadily as something awakens deep in the stone beneath the sanctuary of belches.

Within the darakhul city of Gonderif, at the nadir of a thousand‑foot‑deep chasm, is the site of a vile tournament where Gonderif ’s most rebellious slaves and war prisoners are forced to fight to the death—and through undeath after undeath—until only one living champion remains. Whether they came as captives or as liberators, the PCs must survive the Undying Tournament.

A kobold king lair suitable for four or five 8th-level characters. King Qalqat is gathering followers in a bid to establish his own realm. A wanted dragonborn fugitive, Brustival recently joined his ranks and his power. However, Brustival is now a wanted man and there's a bounty on bringing back his head to the local magistrate.

She lay down her sword and wept; her tears are the water. She lay down her body and slept; her bones are the fountain. Atop the mountain, at the war’s end, a place for gods to wonder.

The General who commanded the successful and profitable Crossroads Mercenary Company turns up murdered in his home, on the very eve of his scheduled announcement of which of his ambitious captains he’s chosen to succeed him as commander-in-chief. Every one of those commanders was in the house when the murder occurred, so they’re all suspects. If that’s not enough to keep things exciting, the clock is ticking down to zero. The General made a pact with devils years ago, and unless the murder is solved quickly, an infernal gate will open, allowing devils to flood through the General’s mansion into the world at large.

A welcoming desert oasis offers respite from the searing wasteland, but this paradise has perils. Castle of Sand is suitable for three to five 4th level characters.

"Bloodwood of the Cruor Circle" is an alseid and blood hag lair suitable for four or five 10th-level characters. This adventure can be completed in a single session. The Cruor Circle, a coven of dark druids led by a blood hag, has taken over control of the local alseid herd with the power of the blood. Within the forest, those who do not make proper sacrifices are stalked by the alseids and taken to the Bloodwood. Within the Bloodwood, captives become blood sacrifices, empowering the creation of sap demons, blood ponds, and other twisted products of the dark druids.

Rumors fly up and down the river. People have vanished. Bodies have appeared, horribly mutilated. Death stalks the streets of Zobeck, and the people are afraid. Will you stop the killer before he strikes again, and again … and again?

This is an adventure for four 6th to 7th level PC's that may be completed in a single session. The Untamed are a street gang in a busy city. A recent change in leadership has transformed the members from pickpockets and second-story thieves into kidnappers for an inter-dimensional aberration named Xlrieh'oc. Their hideout is now a strange and wicked factory, capable of extracting the firm essence from a person; the process leaves the victim partly ethereal and their form no longer casts a shadow. Although most victims die during the procedure, those who survive are conscripted into the gang. The extracted essence is crated and shipped to the aberration's home plane through a breach between worlds in the hideout's backroom.

Let nothing end the Feast by the River. Let the celebration of our enemy’s vanquishing ring out night and day for eternity. Let the bones of our enemies and our prey mingle below our feet. This is your time, our time, the best time. —Queen Gellao on the eve of her victory over the followers of Dur; decreed at the River’s Bend feast hall

Fight the Monster in its Den … If You Dare! Book of Lairs brings you 24 great monster lairs for 5th edition! Each of these exciting and unusual battlegrounds comes with a complete short adventure, including a hook, area hazards, tactics, and treasures. Stage your 5th Edition fights in unforgettable locations like: Alchemist’s Guildhall Necromancer’s Cistern Clockwork Tower Den of the Rotten Kings Lost Halls of Everforge A Pirate Cove Crypt of the Warlock Citadel of the Void Dragon A Dark Grove Lost Fane of the Serpents Branches of Yggdrasil Tomb of the Scorpion Prince Sky Stairs of Beldestan Imperial Ghoul Outpost Umbral Vampire Lair And 10 more! Designed by some of the top names in the RPG industry, Book of Lairs is sure to add an aura of wonder and mystery to your game! Book of Lairs uses standard monsters as well as surprising new creatures from Tome of Beasts, and both monster books are required for maximum playability.

Rennie and Linde are in search of their father, Petring, who they saw disappear into the crypts beneath town. The crypt is thick with supernatural shadow. Torches can be lit from a brazier of green faerie fire in the entrance that cuts through magical darkness. The torches burn rapidly, and the PCs must travel quickly to preserve their light until they reach the funeral pyre in the heart of the crypt. There they can learn the way to the Carrion Shrine of Qorgeth.