*Waves* to everyone. I am a new member, but have played all the Geneforges (5 in demo only so far) and been lurking here for a couple years.
I was pondering Shaila as a possible PC, as she did startrebel, went to the Shapers for "help" and possibly would have ended at the Foundry for "analysis" on how to help her. Sticking that rod in her chest would be what Rawal would do.
But, I think I am inclined to believe this is a new PC, or the one from 3, who may have been sent to Drypeak for a mission, possibly to obtain some information about geneforges, or to replace something after Southforge fell, and got injured or attacked and wandered about until absconded with by Rawal or one of his people.
Rawal's guardian there in the spire says he hoped for an agent to handle business, and was using you to see how you'd work out, and an agent would be spying in Drypeak reasonably.
Or, it could be someone new. One thing Jeff does well is allow for imagination and creativity, if one doesn't cheat their way through before playing it straight up a time or two first, and that would make sense.
The right answer was already said. The PC is anyone you want it do be .
Micah