Very glad to be put in the dark, as you might suppose? (9)
I believe the answer is:
delighted
'very glad' is the definition.
(delighted means very glad or pleased)
'put in the dark as you might suppose?' is the wordplay.
I cannot quite see how this works, but
an anagram of 'the' is 'hte' which is within the answer.
This explanation may well be incorrect...
'to be' is the link.
(Other definitions for delighted that I've seen before include "Joyful" , "Happy" , "Overjoyed" , "Greatly pleased" , "Over the moon" .)