Strange passion returning in midweek? (5)
I believe the answer is:
eerie
'strange' is the definition.
(eerie means odd or strange)
'passion returning in midweek?' is the wordplay.
'passion' becomes 'ire' (ire is passionate anger).
'returning' says the letters should be written backwards.
'in' indicates putting letters inside.
'midweek?' becomes 'ee'.
'ire' backwards is 'eri'.
'eri' going within 'ee' is 'EERIE'.
(Other definitions for eerie that I've seen before include "Unnerving" , "Awesome" , "Spooky, creepy" , "Uncannily strange" , "Bloodcurdling" .)