via SCIFI WIRE -- Rick Berman: "We've also just finished the script for an episode called 'Vanishing Point. It's an episode that's hard to talk about without giving away the secret, but it's based around a transporter accident and it features Hoshi, who's in virtually every scene of the show. That's episode #10."
Edit: Production took place mainly on standing sets from Wednesday, October 2, to Friday, October 10.
According to www.treknation.com, this is rumoured to feature Hoshi Sato changing into a 'ghost,' turning invisible and gaining the ability to pass through walls. Although the entire crew thinks she's dead, she needs to find a way to communicate with her crew and warn them about an alien plot to blow up the Enterprise.
Wasn't this the plot of the TNG episode 'The Next Phase'? (La Forge and Ro were thought to have died, but were really just 'out of phase' and could pass through walls, but couldn't let anyone know that a Romulan was trying to destroy the ship.)
Actually, Kirk was thought to have died in the TOS episode 'The Tholian Web', and appeared as a ghost, but he was just out of phase too, and the Tholians were about to destroy the ship.
If they've run out of stories already......?