PG 356, Is the Observation test required to spot the great white Ophirian stallion necessary, or is it an opportunity to generate momentum for the PCs?
PG 356, The Chittering Swarm, 2nd paragraph: "They pulled them from his warhorse and fired arrows" -> They pulled him down and then shot him with arrows?
PG 356, The Chittering Swarm, 4th paragraph: "They were men, but were not men," -> Intended phrase?
PG 356, 2nd to last sentence: "both watching as the terror grisly tableau unfolded before them." -> "both watching IN terror AS THE gristly tableau unfolded..."
PG 358, Step Into Darkness, 1st paragraph: "Following this trail takes the player characters through stone arches and into a ruined building, where a jagged hole in the floor leads into the earth. Rough-carved steps descend into pitch darkness. It was once some sort of reservoir, but now there is a jagged hole in the floor, a passage down beneath the earth, rough-carved steps leading into pitch darkness." -> Two versions of the same sentence
PG 358, Step Into Darkness, 4th paragraph: "or to pursue the ghouls into a subterranean tunnels," -> singular tunnel
PG 359, 3rd paragraph: "The gamemaster is encouraged to improvise this portion of the adventure, if desired, adding potential hazards in the form of crumbling walls, unstable terrain, and cover behind with Shemitish enemies might use bows against the player characters." -> fix the phrase "and cover behind with"
PG 361, Throne of Bones, 1st paragraph: "The magnificent throne of the king of Zuhal-sar is set with gold, lapis lazuli, and other precious metals, and alongside it are four smaller thrones, those of the king’s royal consorts. Now all are besmirched with foulness and verdigris" -> This may be overly particular, but only copper, brass, and bronze oxidize to produce verdigris. Who cares?
PG 361, The Main Course, 1st paragraph: "...is the entry to into the temple of four of their number from elsewhere in the temple" -> Review the sentence, perhaps "...is the entry into the temple by a pack of four ghouls from elsewhere in the temple"
PG 361, The Main Course, 2nd paragraph: "The ghoul’s chanting" -> "The ghouls' chanting"
PG 362, 1st sentence: "a stinking wind wails from out of the pit" -> "a stinking wind wailing from out of the pit"
PG 362, The map's title refers to Zuhal-sar as Zuhal-saar
PG 363, Battling the Unspeakable, 3rd paragraph: "Killing the charnel will cause" -> "Killing the charnel GOD will cause"
PG 364, last sentence, "privileged guests the house of" -> "privileged guests OF the house of"
PG 365, A Note On Sources, "Readers might notice that is featured in Smith’s story" -> review sentence... (great way to proffer further reading... "The Charnel God" is a fantastic story)