You got it, it is "SHOCKWAVE, PART II"! To explain...
Can be done in high school... Daniels says sending a message through time could be done while he was in high school.
Surrounded by slithers... the Suliban surround Enterprise.
A mind is a terrible thing to waste... the library in Daniels' world is decimated.
Back to the future... Archer journeys back to his time, which is our future.
Message in a Vulcan's quarters... Archer appears in T'Pol's quarters via message.
Over the top... Archer tells T'Pol that her speech to help them continue the mission put it over the top.