The Rooms of Antiquities, the pleasant female voice can be heard from the earbuds of the electronic tour guide, contain a number of peculiar objects, many of which are not, in fact, ancient. Several of them were in fact thought to be ancient until they were discovered to be forgeries, or merely more modern pieces confused for older ones.
"...Fly's not very smart. Or independent. It'll do what you tell it. And no, it doesn't have telekinesis. Look, try to use it with your staff."
"If you're sure..."
Theo gets the Key out of his bag again, says the words to enlarge it – "The Key which hides the powers of the Dark, show your true powers before me. I, Theo, command you under our contract. Release!" – then drops the Fly card in front of him, and says "Fly, help me fly," feeling ridiculous, tapping it with the staff.
Eventually they get back to Theo's house, and he dismisses Fly and wills his staff into the Key, putting the Key into his jacket pocket and the card into his bag.
He says hi to his dad, walks up to his room, puts the bag down, and then sits at his desk, thinking.
"If I'm the Cardcaptor, and I released the cards that are going to cause the great catastrophe you keep talking about, then it's my fault, and I have the ability to fix it, so I kinda have to."
"It just seems like a lot of responsibility, and I'm not exactly the best person for it."