What do you do when a character creeps into your writing room, a character who isn't part of the WIP you're required to send to your advisor/agent/editor? Do you trust the Muse and write whatever this character whispers in your ear? Do you run away from her and focus on your deadline? Or, do you work on both? Do you ignore your hygiene and your dog and career, and life, in general (sorry for the melodrama) and write what the Muse provides because that fire burning in your soul, the one that's smoldering in your fingertips, won't extinguish any other way? You're the story's agent. You must give her a voice, yet the other WIP, and its revisions and its deadline aren't as appealing, not as fun, and is due real soon.
Any advice? Do y'all work on both WIPs? Run away from one? Or, in the words of the great Tim Gunn: "Do you make it work?"