What does Mulch do once inside Fowl Manor?

Mulch walks along and sees cameras. He asks Foaly to find out at what the three cameras are pointing. They find that it's a painting of Artemis Fowl, Senior. Mulch presses his ear to the painting and then pulls the picture away from the wall. Behind it is a safe. Mulch works on the dial but when it opens, he finds only human currency.