Engrossed in dire vet's performance (7)
I believe the answer is:
riveted
'engrossed' is the definition.
(I've seen this in another clue)
'dire vet's performance' is the wordplay.
'performance' indicates anagramming the letters.
'dire'+'vet'='direvet'
'direvet' with letters rearranged gives 'RIVETED'.
'in' is the link.
(Other definitions for riveted that I've seen before include "Immovably fixed" , "Made immovable - with steel pins?" , "Fixed (as attention may be)" , "Completely engrossed" , "Rooted to the spot with metal pins" .)