"Doom Croaker's Branches" is a lindwurm lair suitable for four or five 4th level characters. This adventure can be completed in one session.

In the thriving city of Zobeck, a breakdown of the vital Puffing Bridge is throwing a wrench into the entire city. Workers can’t reach their jobs, merchants and goods can’t reach markets. In short, if this problem isn’t fixed quickly, there’ll be chaos in the Free City. Of course, this isn’t a simple mechanical breakdown but an act of sabotage, and the saboteurs are still at work when characters arrive to investigate.

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.

Multiple groups seek a thug’s girlfriend through the streets and alleys of Zobeck. The adventurers’ lives may depend on finding her first.

"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.

Qorgeth’s fanatical undead followers await a messenger from their dark master. They whisper blasphemous prayers at blood drenched altars in total darkness, their profane chants calling Qorgeth’s demonic emissary to the mortal world. The unspeakable evil that now threatens Midgard’s Western Wastes was awoken by the well intentioned mistakes of a man named Petring, a loving father who was seduced by Qorgeth’s lies. It falls to a party of PCs to undo his cataclysmic mistakes and protect Midgard from the coming of a demon prince.

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 Riverfront Rat Gang" is a ratfolk lair, also featuring wharflings and a doppelrat, designed for five 1st level characters. This adventure can be completed in one session. The old dockyards once served as the primary center of commerce in town. Years ago, political pressure from an influential merchant who wanted the docks to be loser to her business forced shipping concerns to move their docks upriver. The new facility accommodates larger ships, and the old docks fell into disuse. Talk of converting the property into a set of riverside shops died when a rat infestation proved to be an unsolvable problem. Thus, the old dockyards have been decaying for years. This situation suited a former thieves' guild member, a ratfolk rogue, named Matimer Creel. A botched robbery (for which Matimer blamed his accomplice) turned the guild against Matimer, who fled from certain death at the hands of the guild master. He hid out in the old dockyards, confident that not even guild members bothered to go there. From there he began to exact revenge against the guild by ruining its plans or stealing directly from it. He also befriended the rat population, thanks to a golden rat's tooth he acquired, and the vermin help with his schemes. A trio of rat-like wharflings and a doppelrat, washed up on the riverbank near the docks, have joined Matimer's retinue.

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.

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.

A doctor who helps with rare and socially debilitating diseases who welcomes all to her doorstep suddenly becomes reclusive...and her patients are no longer able to be found. Adventurer's are hired by a powerful merchant who had committed her son to this doctor, and they need to find him and bring him home.

"Monument of the Thunderer" is a desert half-dragon lair intended to challenge a party of four 7th-level characters. Near the city state of Makuria, on a small island in the middle of the Green Nuria River, an immense stone sculpture of a dragon watches over the mighty Red Cliffs and the waterfall that pours off them. The monument was built by ancient worshipers of the Mharoti conqueror known as Zulatil the Thunderer, but now serves as a base of operations for a band of sinister thugs who call themselves the Red Cliff Raiders.

The Vault of Pallon the Pious is an adventure for four 2nd level PCs. A famous pirate captain came to worship a lawful god in his final years. After a lifetime of plundering, pillaging, scuttling, and murdering along the coastline, the fear-inspiring Pallon the Merciless rebranded himself as Pallon the Pious. But, a history of violence is a hard thing to reconcile, and the salty old dog slowly succumbed to madness. His most precious possession was a set of scales that reflected perfectly his own inner conflict. The Scales of Misjudgement are buried deep in the treasure room of his crazed rock-island vault.

A shadow goblin lair suitable for four or five 4th-level characters. A growing band of goblins led by a powerful shadow goblin named Hurkl are demanding a toll to travelers on the Dancing Shadow Path. When the heroes are chasing a fugitive through the area and come across the toll...what will they do?

This adventure is suitable for four 6th to 7th level PC's and may be completed in a single session. Oithois the exceptional ice mephit and his foul underlings have uncovered a powerful relic at the entry to ancient ruins. The monstrous mephits seek to crack a hole between the material plane and their icy home world. Oithois plots to lead an army of elemental lackeys and conquer the civilized outposts of the north. This ice mephit has studied the machine and is confident he can open a gateway to the elemental plane of ice. PCs are approached by a frostbitten traveler, who pleads with them to assault the terrace. The adventurers must mount an attack against the mephits, contend with an unintentionally summoned young white dragon, and defeat Oithois upon the icebound terrace.

"The Hive" is a spawn of Arbeyach lair, also featuring giant termites and termite swarms, for five 6th-level characters. This adventure can be finished in one session. Several mounds in the Forsaken Hills are the dens of voracious termites that have added flesh to their diet to supplement dwindling wood supplies. At night, swarms of termites hunt and devour prey. They swarm over victims in wooden carts and wagons, and bring the dismantled wood back to their mounds. Three spawn of Arbeyach, searching for a location to summon Ia'Affrat, Arbeyach's herald, discovered a mound filled with particularity nasty termites and used their vermin empathy to gain acceptance. They dug out a cavern beneath the mound, and now use the termites to protect themselves and gather food while they complete a difficult ritual involving dozens of sacrifices. The final sacrifice is prepared and the spawn are finishing their ritual when the party arrives.

"The Warlock's Crypt" is a fext and noctiny lair suitable for four 9th-level characters. This adventure can be completed in a single session. An ancient warlock king known as the King in Silver, whose patron was Death itself, knew he was growing old and would soon die. The aging king pledged the souls of his two sons, the Black Prince and the Red Prince, to Death in exchange for his own eternal life. As the final worlds of the pledge pass his lips, the old king collapsed to the ground, dead. Elsewhere in the castle, the two young princes died suddenly in their sleep. All three were interred in the royal crypt within a nearby burial mound. ultimately, the king got what he asked for - he and his suns were returned to life as fext in the service of Death itself. When the fext awoke and climbed out of their coffins, they were confused because it seemed they were trapped within the small royal crypt. Then, the King in Silver discovered a secret door leading to a hidden stone stair that descended into a complex of ancient tunnels and chambers. At the far end of the complex, the fext discovered a second set of ancient stone stairs leading up through a shaft to a hidden exit on the surface. The three fext now lurk within the lower chambers, doing their patron's dark bidding. When commanded, they creep forth from the crypt to spread death during the dark of night.

An evil oracular being has taken up residence in a lonely valley. The only access to the valley is through a thick, dead wood whose shadows draw out foul memories from those who travel there. The oracle, Lurinax, has recently divined the season in which the world will end. This knowledge is greatly prized by many, so the evil fortune teller hides in his lair, protected by maddening winds and the souls of those he slew to obtain his knowledge. In this grim and dark adventure for tenth- and eleventh-level PCs, the party must travel the trail of shadows, face the manifestations of Lurinax’s victims, and finally the evil oracle himself.

Bodies are turning up in a city (or large town). The organs of the victims appear to have been turned to solid crystal; in a gruesome twist, the hearts of the victims have been carefully removed. The mayor and the guard captain have hit an impasse in their investigation. Agreeing to assist in finding the murderer, the party find themselves under attack by infernal assassins as they follow the clues to a gemcutter's workshop. In this rich and devilish adventure, the party must find and face a murderer and a charming devil.

The nefarious master wrestler Dib, the goblin, is "terrorizing" the streets of the town (or city). Since his defeat in his roadside fortress, the would-be chieftain has plotted his revenge. Gathering to him a new batch of dim minions, Dib has transformed a stolen merchant wagon into a machine of war. The wagon is powered by several goblins inside who, while devoted to Dib, lack the strength to pedal the thing quickly or consistently. Dib's plan to wreak a path of havoc through the streets has resulted in something a bit more disappointing. In this light-hearted and quirky adventure for four first- or second-level PCs, the party must confront the war wagon, gain entry to it, and defeat its defenders—the lives of several potted plants and a few market stalls depend on it!