The Doctor had taken the bags of blood, and with eyebrows drawn together, was turning them over in his hand. He withdrew the Sonic Screwdriver from his coat just as the... well, the thing... appeared.
He was careful to set the blood down, but he did it quickly. Very quickly. And then he stepped right up to the barrier and glowered.
"Tell me who you are, and why you took these people," the Doctor said.
The tone suggested it was a demand. The Sonic was still in his hand, like a weapon.