Aria yells encouragement to her twin, or possibly a taunt for his failure.

"Indeed," says Havelock gravely, and shrugs. "Their initial attempt failed, at any rate. Her house is somewhat... fortress-like in certain regards."

Madam kept his childhood traps and locks around the house as any proud relative would treasure early projects from a developing young artist. Getting in when you don't know the safe route is extremely hazardous to the health.