The last memory we have of Jacob is the hardest one to think about. We were at a distance, counting him down. He did not fiddle with levers or buttons; he was calm because everything had already been taken care of. He said something I couldn't make out over the rising roar of the machines, right before we counted down to 1.
We're pretty sure he's gone, because if the time machine really had worked, the least he could have done would be to stop by and let us know he was alright.
A B-side: The evolution of Lobsterman (non-canonical; a scientific attempt to explain the horror)