Harry stalked into the room.
"Lemon drop?"
Offered dumblebore.
Harry accepted, and did a check on it. Of course. There was a calming potion and a very mild truth telling potion. Neutralizing it with a bit of magic, Harry popped it into his mouth.
Dumbledore looked pleased
"So dumbledore, for what reason have you summoned me hear today?"
All this while Harry had been fiddling with a shimmery purple-black bit of umbers scale and a bit of silver.
He silently crafted a beautiful ring, complete with a tracking charm only detectable with parselmagic. He teleported it into a strategic place on one of his desks, where it would be noticed.
He also placed a thought dumbledore would absorb, and would pass right through his shields.
The thought is:
Wear the ring.
Dumbledore will wear it, thinking he simply like it, but really it's a weapon.
"Harry my boy! I was just calling you up to see how you are adjusting to school. Oh I remember when your parents were here for their first day."
Dumbledore smiled warmly, grandfatherly.
"You knew my parents!"
Harry said excitedly.
(Obviously faking)
They then proceeded to have a long conversation, both of them faking.
Harry retreated to his room a hour later, with a prize for his effort.
He had snatched a vial with two strands of what was labeled as "dementors essence" a feather from Fawkes and a strand of dumbledores hair