Period of fascination (5)
I believe the answer is:
spell
I believe this is a double definition.
'period' is the first definition.
(spell can mean a period of time)
'fascination' is the second definition.
(I've seen this before)
'of' is the link.
(Other definitions for spell that I've seen before include "Magic words - period of time" , "Put letters in right order" , "Give out letters" , "Stretch" , "Incantation; write in letters" .)