Characters could be extras possibly around edge of scene (5)
I believe the answer is:
runes
'characters' is the definition.
(rune is a kind of character)
'extras possibly around edge of scene' is the wordplay.
'extras possibly' becomes 'runs' (extra is a type of cricket run).
'around' indicates putting letters inside.
'edge of' indicates one should take the final letters (one of the letters on the edge of the word).
The final letter of 'scene' is 'e'.
'runs' placed around 'e' is 'RUNES'.
'could be' acts as a link.
(Other definitions for runes that I've seen before include "Small stones bearing symbols with magic significance" , "Old letters" , "Mysterious letters" , "old characters" , "marks on old tablets" .)