"All-Seeing Eye" is a oculo swarm and night scorpion lair for five 5th-level characters.

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

"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.

"Imperial Ghoul Outpost" is an iron ghoul lair suitable for four or five 10th-level characters. This adventure can be completed in a single session. When a clan of duergar prospectors unearthed caverns not on the their maps, they were particularly excited about a strange new iron orc they found there. not long after mining began, undead horrors emerged to attack the dwarves. Only one duergar escaped, his mind shattered by the experience. The Ghoul Imperium continues to explore the area, and it has its own plans for the newly discovered one.

"Lost Halls of Everforge" is a flame dragon wyrmling lair suitable for four or five 3rd level characters. This adventure can be completed in one session.

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.

Fane of Serpents is a titanoboa lair suitable for three to five 10th-level characters. A rocky butte covered with soaring ruins looms over the landscape. Legend describes it as a monument raised by an inhuman race that was wiped out centuries ago as retribution over foul practices. Locally, the spot is known as Titan’s Height. It rises starkly above the surrounding area, with four terraced plateaus. Each level is covered with the ruins of many-columned halls in an architectural style unlike anything else in the area. Their age and strangeness alone are enough to generate fearful legends. The stories grow worse when travelers or livestock disappear near Titan’s Height, which they sometimes do.

"The Aboleth's Grotto" is a nihileth lair suitable for four 10th-level characters. The adventure can be completed in one session. The small town of Springwell harbors a secret that almost nobody knows about, and those who do conveniently ignore: it sights right over an unoccupied settlement of the deep caverns of the underworld.

"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.

"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.

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 Triangle in Shadows" is an umbral vampire lair suitable for a party of four 15th-level characters. Magic weapons are highly advised. This adventure can be completed in one session. The City Fallen into Shadow is the domain of the fiendish umbral vampires, and they are rarely found outside it. But one named Caragorn has fled the city after coming between the lovers Philadon and Zenobia. Philadon and Caragor, however, are secretly meeting at Caragorn's tower behind Zenobia's back. Zenobia suspects them of collusion, and is seeking out the two male umbral vampires to get revenge.

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

"The Clockwork Tower" is an azza gremlin lair suitable for five 3rd level characters. This adventure can be completed in one session.

"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.

"Ruins of the Umbral Tower" is a shadow fey hunter lair suitable for four or five 8th-level characters. This adventure can be completed in a single session. The ruined Umbral Tower rests deep in the forest, in a marshy region avoided by all but songbirds. Long abandoned by its original occupant, the tower features a malfunctioning gate that connects this place and the Plane of Shadow. The site serves as a base for a group of shadow fey hunters and their entourage of hounds and guardians. The hunters used the gate to travel from their home plane, and they now attempt to bag as many trophies and as much loot as possible before returning home when the gate reactivates.

"House of Reeds and Whispers" is the lair of a pair of red hags, suitable for four characters of 8th level. This adventure can be completed in one session. Two red hag sisters recently exsanguinated an eccentric collector named Nahl Fry and took up residence in his swamp-side home. Liori and Ijith were seeking an artifact from the ancient city of Talitheos, the sunken stronghold of the red hags. They found the artifact, a pair of knitting needles made from blood-infused coral. in Nahl Fry's collection. The sisters yearn to understand how the artifact works, and so they are testing its dark powers against a nearby hamlet. They have knitted rapidly growing crimson reeds that funnel the blood of fauna and farm animals back to the house. The hamlet's leader, Galnas, hires the PC's to investigate. The party must press through the reeds, defeat the sisters' guardians, face the hags, and end the reedy infestation.

Sky Stairs of Beldestan is a vampire warlock lair suitable for four characters of 14th level. It can be a lead-in to Citadel of the Void Dragon, or it can be played independently. For as long as any dragon can remember, the stairs of Beldestan have been a site of pilgrimage, a direct route from dusty earth up to the heavens, where enormous creatures soar and carry sacrifices up to the gods. Its base is well known for the efficacy of the invocations offered there, but very few other than the most faithful dare venture up the stairs themselves: enormous eagles, howling winds, and various inimical undead make the stairs a place that few find congenial for long.

"The Pirates' Cove" is the lair of a blasphemous cult, suitable for four or five 5th level characters. This adventure can be finished in a single session.

Hada the Black, a necromancer who was apprehended during an investigation of five missing orphans perished last night in the custody of city officials. The inquisitor who questioned Hada is certain that the children are still alive. After the characters hear of a contract offered by the city guard, they discuss the situation with the inquisitor. The tired and disheveled man smooths his crimson robes as he speaks.