So is it chronicling the Earth-Romulan War aboard the Enterprise?
I know that seems like an obvious question, but from my reading
before I didn't know the NX-01 was involved.
Check out The Good That Men Do
, if you haven't read it already. It's a fantastic read, and it begins to lay the groundwork for the Romulan incursion into Coalition space, not to mention how Archer & Co. become involved.