The Doctor looks at the sample for a long time, then asks for a different one. As Catherine is removing the sliver with tweezers, it falls and she picks it up with her fingers. It turns her fingertips numb, and makes them wrinkled and old looking. The Doctor drops it on his palm, and it does the same to his hand. His skin recovers almost instantly when the sliver is removed, and he tells her that hers will recover in a day or two. He wonders aloud why the energy absorption is tuned to just one strain of DNA life force (noting that he isn't 'close enough').