I3-4-5: Desert of Desolation
Desert of Desolation comprises I3: Pharaoh, I4: Oasis of the White Palm, and I5: Lost Tomb of Martek. Tracy Hickman was the overall mastermind of these modules.
Tracy cowrote Pharaoh with Mrs Laura Hickman, alongside that Hindustani brilliance which would become B7: Rahasia. The couple sold these two privately in Utah, which did well locally. But they got shafted on an unrelated business deal so sold these titles to TSR, who - in a rare flash of business sense - realised what a goldmine they had so hired them outright. Tracy did I4 instead with Philip Meyers. He did the last one on his own and it kind of shows.
As backstory for I3, Pharaoh Amun-Re once upon a time offended Osiris by his acts of tyranny and blasphemy including the building of a grandiose pyramid to himself. As a result, the god cursed Amun-Re to become a restless ghost whose presence blighted his own land into a barren waste. Only by having his fabulous treasure stolen would the curse be broken, banishing the desert that had swallowed up his kingdom and allowing Amun-Re's soul to enter the peace of the afterlife. The story begins when Amun-Re's ghost appears to the party as they wander the Desert of Desolation that has sprung up around his tomb, pleading with them to risk the traps and guardians of his pyramid and end his curse.
By happenstance this pyramid is the earliest ever Egyptian themed dungeon to ever have a presence in Dungeons & Dragons.
In the course of healing the land, in classic early Hickman railroading, the party accidentally looses a Wishmaster-esque evil afrit. The party has to fix THAT by robbing more graves and collecting soul-gems. The first one is had in the Pharaoh's tomb in the first module. The other two are got in the course of I4, starting with a temple of Set and culminating in the tomb of Badr al-Musak.
I4 ramps up the Islam, by way of the Ibn Ishaq Sira. Hickman and Meyers pose a holy cold-war between the Thune Dervishes and the Symbayans. The Thune protect ALL the holy sites of the wastelands, whatever their supposed "alignment". The pegasi-riding Symbayans are monotheists to Anu. I4 would have you side with the latter against those intolerant fanatical ... pluralistic pagans. Well at least Hickman (and Meyers) allowed the Thune have an ethos (as The Great Lebowski might put it).
The finale I5 is mostly in one final tomb, that of Martek, where Hickman rewards you with a ... Liahona. Well so much for all the Islamic themes, here's that Hickmanite Mormonism you'd been wanting.
It was all compiled into a single book and retconned for the Forgotten Realms series. Hamfistedly. Although not such as to ruin them.
Also the skate-ship in I5 was reused (maybe stolen) for the glass sailship in Dragonlance's Time of the Dragon. Since Hickman started the whole Dragonlance thing why not, we guess.