The Doctor had raised the sonic the second the mummy stepped out of the closet, finger on the button as it hummed and buzzed at the mummy's back, taking in all of the information that it could gather about the individual's height, weight, composition, the matter of animation, and all other various aspects that seemed to be important. Sweeping down, the Doctor pulled out yet more information about the linen, the organ cavity, about the preservation techniques, and the origins that that narrowed the mummy's origins down to. Sweeping back up, the Doctor had figured that he'd finish up gathering whatever other information that the sonic could pick up that seemed to serve a purpose, but as he reached the mummy's head with a wide gesture, the beam sweeping over everything in front of it, mummy and Amy alike, the sonic started to spark, the buzzing heightening before the light suddenly dimmed and the end began to smoke.
The Doctor dropped the sonic, a bit stunned by the sudden overload since it really should not have done that, but it was only a second before his attention shifted back upward, and he realized that not only have the sonic overloaded, but that overload had had an effect secondary to destroying his sonic and all of the data he'd collected.
It had also drawn the mummy's attention away from Amitiel.