Carver grabbed the batteries, poked her head out the door to be sure Finkelstein had gone back into the bedroom, and then quickly ducked into the laboratory to replace them with freshly charged ones. She ran a few excuses through her mind in case the Doctor came back out to see what she was up to, but she didn't want to wait. 

It took her a few minutes to get everything switched out and make sure she hadn't left any traces of disturbance. As soon as she was done, she retrieved Shock and left a lot more quickly -- but no less quietly -- than they had come in. Once they were a good few blocks away, she stopped and looked at her friend expectantly. There was [i]no way[/i] the trickster was going to let her get away with any of that, and she'd rather get it over with.