Here's a link to the trailer, which features John Savage reprising his role as Captain Ransom:
Essentially, the premise is that Captain Ransom survived the destruction of the USS Equinox in the Delta Quadrant. He was somehow beamed off by the Krotownans and held prisoner in the Delta Quadrant. He manages to escape and in fleeing, ends up traveling through an anomaly and ends up back in the Alpha Quadrant, but during the TOS era. He's picked up by the USS Equinox, a miranda-class starship.
The unlikely coincidence of being picked up by the USS Equinox seems a little cheesy to me. But, I do like the idea of him escaping and making his way back to Earth alone. What do you think? Too far fetched?