This involves spells in wide and long ship (10)
I believe the answer is:
witchcraft
'this involves spells' is the definition.
The definition suggests a singular noun which matches the answer.
'wide and long ship' is the wordplay.
'wide' becomes 'w' (abbreviation e.g. in cricket).
'and' is a charade indicator (letters next to each other).
'long' becomes 'itch' (to long or itch for something is to desire it).
'ship' becomes 'craft' (I've seen this before).
'w'+'itch'+'craft'='WITCHCRAFT'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for witchcraft that I've seen before include "Sorcery skill" , "Magic" , "Supernatural power" , "broomstick?" , "[OBI], say" .)