A devastating fall decimates Ista Weyr.
The making of a Weyrleader.
The Conclusion.
Major confrontation at Eastern Weyr, Cygnan team attacks.
How the Cygnans got to Pern.
Pernese learn about Cygnus 4.
Cygnans fly first ThreadFall.
Key relationship starts to develop.
Darian and team arrive on Pern.