As a voice of reason and sanity, I vote against making prank calls. This is the kind of random stupidity that Tomcost mentioned - take away the emotional pressure and everybody goes crazy.
Imp, if you are right, and what you propose is perfectly plausible, then we need to immediately find Gamington and ask him if the girl has the coordinates to the base. If he still has a good enough opinion of us to not let the heroes know where our base is, then good. If he has become disillusioned with us thanks to that carousel of suffering we caused, then congratulations, we have pretty much screwed ourselves over by being irresponsible sociopaths. Who could've thought?
Anyway, sardonic self-chastising aside, we then need to immediately relocate to our backup base and sail away at full speed, leaving the heroes to make their complaints to the complaints department, which is the virus bomb, lying on our throne and set to a proximity trigger.
EDIT: Whatever the situation with Jeanne is, Cerulean and Splintercog's testimonies do not match up. Besides, Cerulean is awful at stealth, but not stupid enough to blatantly implicate herself in the murder unless she, for some reason, wants to be. Something smells seriously fishy here, and I believe that the first thing we should do in the next update is to find Gamington and ask him about the missing girl, Cerulean and Splintercog. Override his protocols if necessary.