Thorn fell backward but when he saw Thorn's eyes, Ca'daan saw something inhuman.
As Thorn lunged forward, Ca'daan caught a glimpse of the empty sockets where his eyes once were. 
mnli hypothesis: As Thorn lunged forward, Ca'daan caught a glimpse of the empty sockets where his eyes once were.  premise: Thorn fell backward but when he saw Thorn's eyes, Ca'daan saw something inhuman.