A Conspiracy of Doors is a Dungeons & Dragons adventure for five player characters of 11th level. It can serve as an introduction to Sigil, the City of Doors, as well as a group of adventurers' first taste of action at the paragon tier.

Days ago, a portal to the Elemental Chaos appeared near the PCs’ home city. Since then, it has grown into an enormous sinkhole that periodically belches fire and brimstone. The rip in reality threatens to overwhelm settlements and a nearby river unless someone ventures through and closes it from the other side. Pgs. 102-107

Your PCs are reaching the upper end of the heroic tier. New worlds are opening up to them—they might have already ventured to the Feywild, for example, and made contacts with inhabitants of that magical plane. Now they are ready to take their first steps into the darkness. The Shadowfell awaits... Vandariel, a shadar-kai witch who calls herself the Voice of Pain, is a fanatic devotee of the Raven Queen. She has founded and become the self-proclaimed high priest of a bizarre cult, the Lords of Pain, whose purpose is to bring more fey into the shadow pact with that goddess of death. Although the original shadar-kai entered this pact voluntarily, and the race breeds true, Vandariel is consumed by what she sees as a divine mission to reveal the mystery to all fey—whether they wish it or not. Those who do not come voluntarily to the truth are brought against their will. Dark stalkers move like the night, seeking out and abducting suitable subjects. This Side Trek can serve as an introduction to the dangers of the shadow realm. It works well for PCs who are approaching the paragon tier, since it presents a reasonable challenge for characters of 10th level. It is suitable as a climactic encounter for lowerlevel adventurers, as well. It consists of only two encounters.

A group of snaketongue cultists has occupied an abandoned, partially sunken temple near a swamp. They grow impatient waiting for their yuan-ti master to join them, unaware that he has been slain by a rival faction of yuan-ti. Frustrated, the cult strikes against nearby villages in the hope of drawing the favor of Zehir. Investigating rumors of a serpent cult harassing a nearby town, the PCs have explored the swamp and discovered the overgrown temple. Its once-ornate stone door now hangs off its hinges, providing a narrow space for one character at a time to squeeze through. Pgs. 42-47

An agent of the King’s Dark Lanterns has stolen a cache of gold from the Brelish exchequer. Hunt him down, retrieve the gold, and thwart whatever else the rogue agent is plotting. Pgs. 28-65

A short 2-combat side trek: After confronting an ettin and its pet owlbear, the PCs descend into an ancient ruin holding a portal to another plane, protected by a naga, an eidilon and a sea of serpents.

At the behest of Orcus, Demon Prince of Undeath, a mighty deathpriest hierophant has begun assembling a powerful strike force. He intends to launch the first of many assaults on the world, readying it for his master’s arrival. With the help of potent allies and grand rituals, the PCs have discovered a route to the Abyssal headquarters of this hierophant. This delve begins as the PCs teleport from the world to the first of a complex of interconnected chambers deep in the Abyss, linked only by portals. Pgs. 126-131

Stormcrow Company—an unsavory band of adventurers—haven’t been seen or heard from in years. Rumors of their accumulated wealth have spread far and wide, and if they have truly been slain, that treasure is just waiting for adventurers to come and collect it. But is anything ever as easy as it seems? Pgs. 10-28

"Gnolls have captured the heroes! After stripping the characters of all equipment except their armor and clothing, the gnolls drag them to an expansive briar maze known as the Twisted Thickets and set them loose. Then, armed to the teeth, the gnolls hunt down their prey. The characters must survive the hunt and outwit their pursuers. Stripped of your armor and weapons, you are cast into the Twisted Thicket and hunted like rabbits. If you want revenge, you must first survive Yeenoghu's evil Hunters. After dealing with the gnoll hunters, the heroes can try to reclaim their lost equipment and exact revenge on the tribe, which lairs in the caves beneath Dead Gnoll’s Eye Socket." Pgs. 2-14

E2, following up on Death's Reach, the PC's first travel to Sigil following the smuggled remains of the primordial Timesus. The pursuit then leads into the Abyss, through the White Kingdom to face Doresain, the Ghoul King, exarch of Orcus. The module certainly is epic, placing the PCs up against powerful monsters like greater demons, death knights, and a demilich. It may be frustrating that the PCs arrive too late to disrupt the plot (have to allow for the finale in the next adventure) but taking out Orcus' right hand ghoul may be satisfying. Includes a skill challenge for crossing a portion of the Abyss For environments, City refers to Sigil.

The hobgoblins were not the only forces that remained after Kalarel was slain. Before the Keep’s portal was fully sealed, evil spirits from the Shadowfell escaped into the Nentir Vale. They were drawn to Kalarel’s own dark soul, which remained in the mortal world thanks to a spirit-orb the priest had created to prevent him from moving on after death. The presence of these malignant spirits caught the attention of a frost witch called the Rime Mistress and her followers—unaligned territorial beasts—who rose up to defend their domain. The Rime Mistress knows that the spirits present a greater threat than the hobgoblins do, so she and Prang, the Iron Gauntlet leader, have agreed to an uneasy truce. Thus, the hobgoblins and the creatures of the Cairngorm Peaks are united in their struggle against Kalarel’s spirit army.

Uncover a Hidden Legacy A lost passageway on the upper level of the most infamous dungeon in Faerûn has recently been uncovered. When a patron hires a band of adventurers to brave the dangers of Undermountain, a search is on to uncover secrets of an apprentice of the dungeon’s lost creator – Halaster.

"And they bade their slaves, 'Build unto us tombs to rival the palaces of the gods, for there shall we live or lives and sleep our deaths in splendor.' And the people of Maru-Qet wore their fingers down, broke their backs, burst their hearts to obey. Indeed they raised up great tombs to rival the palaces of the gods. And their masters were well pleased, for it was as gods they saw themselves." The brown dragon Urum-Shar lurks in a strange tomb, plotting schemes only a wyrm of incredible power could understand. Expanding on content from Draconomicon: Chromatic Dragons, this adventure takes the heroes into Urum-Shar’s dark and trap-filled lair, where they will eventually face the powerful dragon herself. The dungeon heavily employs the use of traps, with fewer monsters. The upper tomb consists of a great puzzle of twelve rooms, and the lower tomb contains the dreaded Urum-Shar, an ancient brown dragon and heir to the lost draconic empire of Maru-Qet. The dungeon has special protections against scrying and other divinations, as well as teleportation. Pgs. 55-90

Long ago, a powerful lich threatened the kingdom and was destroyed by mighty heroes. Though its phylactery could not be found, a powerful curse was laid upon the lich, trapping it inside its phylactery. This fading magic can’t hold the creature muchlonger, so the PCs must enter the phylactery itself in order to destroy the lich before it escapes back into the world. Pgs. 144-149

Many years ago, Evard came to Duponde to destroy his rival Vontarin, a powerful wizard who lived in a manor at the edge of town. The two mages met near the walls of the abbey of St. Avarthil and dueled all night long with black spells, laying the old monastery in ruins with their magic. In the morning, the surviving friars found Evard dead in the wreckage and buried him in the town’s graveyard. Vontarin was never seen again. Now, almost fifty years after his death, Evard’s final curse is about to descend on the town and everyone within it. Also available in Dungeon Magazine #219 Pgs. 30-90

Long ago, when the Dragonborn Empire of Arkhosia thrived, the flying citadel Ustraternes was undone by tiefling magic. Now, a dragonborn zealot with dreams of renewing the lost glory of his ancestors explores the ruins—and unleashes a plague of rampaging drakes on the terrified locals. The story offers PC's the chance to tame a Warwing Drake, disperse a mob, parley with undead, and battle within an alpine meadow that defies gravity.

Every fifty years, a pair of storm titans met to pray in an isolated and well guarded cloud temple. This time, they have obtained a copy of the fabled Ritual of the Primordial Gate and are exploring its secrets in hopes of bringing a lost primordial to the world. Divine messengers are sent to the PCs to enlist their aid in disrupting the storm titans’ efforts.

New to Loudwater, the heroes learn of a tower locked in ice in the nearby wilderness. Traveling there, they discover that the tower’s master left many surprises behind for the unwary. Also available with e 5e solo conversion: https://www.dmsguild.com/product/247505/DD-Solo-Adventure-Menace-of-the-Icy-Spire-5e-Solo-Conversion Pgs. 4-22

Numerous towns sit in the shadow of Rak’Sarn, a mountain of flames and death. Each day near sunset, the volcano lets loose a blast of molten rock and ash, and the ancient red dragon Dal’Sarnquin swoops down the mountainside. By the time dawn breaks, another settlement has been burned to the ground. The PCs must track the dragon to his lair and defeat him before more towns are destroyed. Pgs. 196-191

A group of mysterious, sea raiders— capable of appearing from out of nowhere, striking, and disappearing— has terrorized a group of coastal states for some time. Now the leader of the states has asked the characters to infiltrate the raiders, find out how they operate, and put a stop to their activities. But once the heroes join the raiders, things aren’t as clear as they were led to believe. Will they succeed at their mission? Or join the raiders themselves? Pgs. 54-82