Storyline inspiring current TV try-out, perhaps (5)
I believe the answer is:
pilot
'tv try-out perhaps' is the definition.
(trial episode of a TV show)
'storyline inspiring current' is the wordplay.
'storyline' becomes 'plot' (eg the plot of a film).
'inspiring' is an insertion indicator.
'current' becomes 'I' (symbol for electric current).
'plot' placed around 'i' is 'PILOT'.
(Other definitions for pilot that I've seen before include "Guide (e.g. of ship through harbour)" , "Plane flyer" , "may be up in the clouds" , "Steer (a ship or plane)" , "Plane's operator" .)