ENT Season 4 Episode 16 Divergence

Plot

With the ship unable to decrease speed below warp 5, and the warp core reaching dangerous levels, Columbia and Commander Tucker rendezvous to provide assistance. However the crew realise that the transporter cannot be used at warp, so the ships will need to maneuver in close proximity in order for Tucker to be transferred. Captain Archer releases Lieutenant Reed from the brig to perform the transfer. Once on Enterprise, Tucker successfully performs a rapid non-standard cold boot on the warp engine, which purges the Klingon subroutines. Tucker then agrees to remain onboard temporarily to assist with repairs.
Meanwhile, physician Antaak and a badly beaten Doctor Phlox update General K'Vagh on their progress. K'Vagh contacts Admiral Krell, who tells him that if a cure is not completed soon, the facility will be eradicated in order to contain the disease. Back on Enterprise, Archer questions Reed about his recent actions, and is contacted by Harris from Section 31, a secretive agency within Starfleet. Harris reveals that Phlox is on an important mission and little else, but Reed reveals his location as Qu'Vat; Harris contacts Krell, to inform him that Enterprise is on the way, and Krell reveals that he used Harris. Enterprise arrives at the colony, and Archer beams down to the base with Marab to confront the Klingons and Phlox.
Krell's Klingon battlecruiser and two Birds of Prey arrive in orbit and Krell orders the ships to destroy the colony. Enterprise attempts to intervene but is engaged by the Birds of Prey. Columbia arrives and joins combat with the two Birds of Prey, while Enterprise impedes the battlecruiser. Meanwhile, Phlox infects a voluntarily restrained Archer, as he needs human antibodies for the cure. Antaak then transports a canister of the virus onto the battlecruiser which infects the crew, including Krell. Needing the cure from Phlox, Krell stands down the attack and the Klingon High Council soon agrees to distribute the cure throughout the Empire.
Harris contacts Reed, thanking him and confirming that the plan proceeded as per Section 31's projections, stabilizing the leadership of the Klingon Empire while scaring it off from augment experimentation.