Calm once they had got themselves together (5,5)
'together' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for collected that I've seen before include "Came together" , "Gathered" , "Also cool and calm?" , "Brought together" , "composed" .)
I'm afraid I can't explain this answer.
Can you help me to learn more?
(Another definition for comes about that I've seen is " happens".)