Herg --> should be lower-case-h herg throughout (like "control his horse", not "control his Horse")
The beast snorted and fidgeted in agitation. --> delete "in agitation". It's unnecessary: you've already shown the agitation with the snorting and fidgeting.
loosing his shoulder bag --> losing his shoulder bag
Unlike most other stars it never twinkled and it moved around the sky in a curious retrograde way, unlike the other stars. --> delete "unlike the other stars" at the end (it's repeating the start of the sentence, and is implied by "curious" anyway).
“Go on.” she nodded. --> “Go on.” She nodded.
“It's a beacon, a guide. “Meru replied. --> “It's a beacon, a guide,” Meru replied. (comma, close quotes)
what looked like a women --> what looked like a woman (singular)
The Herg's looked up --> The hergs looked up (no apostrophe)
Last few paragraphs (from "Miria was frozen to the spot"): maybe mix up/find synonyms for "blazing fireball" (ball of flame, burning sphere?).