Conan the Barbarian #89 – “The Sword and the Serpent” – Roy Thomas/John Buscema/Ernie Chan
This one continues from last issue, with Conan, Bêlit, and Zula fleeing through the passages of the royal palace in Luxur. They find the trap door that leads to the underground tunnels but have to kill some unlucky guards that happen to be patrolling the area. More guards chase them through the tunnels and Bêlit gets confused at a branching of passages, so they pick one at random. It turns out to be the “forbidden passage”, making the guards reluctant to continue their pursuit. The guards end up turning around and leaving when they encounter someone else in the tunnels … a mysterious figure wearing a serpent ring.
Bêlit is eager to return to Asgalun and gain revenge on her uncle (Nim-Karrak) for stealing her father’s throne and sending him to his death. Conan has already promised to help Zula get his own revenge which pisses Bêlit off, but when she mentions Nim-Karrak’s wizard is named Ptor-Nubis, Zula says that’s the Stygian who sold him into slavery and agrees to come with them to Asgalun so he can get vengeance. In the throne room, the wizard Thoth-Amon makes a dramatic entrance and offers to help Neftha keep her newly-won throne. She agrees, especially since Thoth-Amon says he’s already taken steps to eliminate Bêlit and her companions. In the tunnels below, Conan’s party stops to rest but Bêlit rises and wanders into a passageway, still asleep … or possibly 
under some kind of spell. She encounters a serpent with a Medusa’s head that tries to kill her, but Zula (who also felt the siren call but was better able to resist it) saves her. The serpent grabs Zula in its coils and comes close to killing him, but Conan distracts it long enough for Zula to kill it. Conan recognizes the creature as kin to the serpent-thing he fought in Numalia, way back in issue 7, and mentions that it was sent by Thoth-Amon. They continue down the tunnel but are soon ambushed by serpent-men, who can change their form to mimic other creatures. Conan is almost killed by serpent-men posing as Bêlit and Zula, so he’s understandably paranoid when the real ones show up. He makes them say the phrase “Ka Nama Kaa Lajerama”, which he learned from Red Sonja (in issue 24) and which no serpent-man can say or even stand the sound of. Further down the tunnel, they run into some of Bêlit’s corsairs but Conan uses the magic phrase and reveals them as
serpent-men, who flee before the power of the incantation. Conan and company emerge from the tunnels and soon find a trading vessel on the river that can take them back to the coast. This is a pretty good story that gives us our first real look at Thoth-Amon, who will (eventually) become one of Conan’s most implacable enemies. In the original Robert E. Howard stories, Thoth-Amon is only mentioned a couple of times and he and Conan never actually meet (nor are they even really aware of each other’s existence). But L. Sprague De Camp and Lin Carter made Thoth-Amon into Conan’s archenemy in their pastiches, most of which are set years (or decades) after this period of Conan’s life. But it’s cool to see Thoth-Amon in person, even if he and Conan aren’t really archenemies yet.
Conan the Barbarian #90 – “The Diadem of the Giant-Kings” – Roy Thomas/John Buscema/Ernie Chan
This one continues from last issue, with Conan, Bêlit, and Zula sailing their stolen boat down the River Styx towards the coast. They know they can’t sail right into Khemi, so they abandon the boat and head overland to meet up with Bêlit’s crew on the coast south of Khemi. Conan uses the boat’s crew as bearers, promising them their freedom once they reach the coast. Back in Luxur, Thoth-Amon uses sorcery to warn Nim-Karrak that Bêlit will soon come looking for him. Neftha values Nim-Karrak as a puppet ruler for Asgalun, but she has other plans brewing, like the destruction of Harakht, the Hawk City. Elsewhere, Conan’s band stops to rest but the Stygian bearers are afraid, saying the area is cursed. An earthquake seems to confirm their fears and one of them falls over a cliff
into a crevasse opened by the quake. Bêlit tries to save him (since he was carrying the food) and they all end up climbing down to retrieve him and his burden. They find caverns opened up by the earthquake and Bêlit goes exploring, finding a tomb with the skeleton of a giant beside it. Inside the tomb is a giant-sized diadem, which Conan recalls hearing stories about (back in issue 7). He and Bêlit explore further, looking for more treasure, but find only a huge cave full of bats. The Stygians knock Zula out and try to flee with the diadem, but when they touch it the giant skeleton comes to life and grows its flesh back. It puts on the diadem and devours some of the Stygians, while Conan tells Zula to climb up to ground level and wait to pull him and Bêlit back up. Conan tries to fight the giant but doesn’t get far. Turns out he’s just stalling 
until sunset, which brings a mass exodus of bats from the deep cave, knocking the giant back and giving Conan and Bêlit time to scale the rope. The giant grabs Conan’s leg but he throws his sword into its face and climbs to safety. Bêlit is a little disappointed to leave the bejewelled diadem behind, but figures she’ll soon have jewels aplenty when she kills Nim-Karrak and reclaims her father’s throne. This is basically a filler issue, written to give Conan and the others something to do on the long trip back to the coast. Conan mentions hearing about the diadem from Aztrias in issue 7, something we didn’t actually see. But there was a mention of the diadem in the original story (“The God in the Bowl”) on which that tale was based, so I guess we can assume Aztrias told Conan about it between panels.