When last audiences saw the characters of Nikita three weeks ago, they were dealing with the returns of Owen, Amanda and Ari. Their situation is not improving.
As the action of 'The Sword's Edge' begins, rogue agent Edward (guest star Jonathan Goad) is questioning Division's motives before revealing himself to the people of Uzbekistan as their newly-elected leader Markov. Ryan sums it up thusly: "One of the Dirty Thirty is the leader of a foreign country."
He declares that a move needs to be made on Edward/Markov when he heads their way for a scheduled visit to the White House, and snaps everyone's heads off while he's doing it.
Nikita wants to know what Ryan's problem is, and in his office afterward he reveals to her that there's a mole in the new Division. She says that she'll put Alex on it, because Alex has experience with moles, but questions if that's really all that's bothering him.
After telling Alex that she has carte blanche to question anyone in Division, Ryan uses an underground tunnel to make his way into the White House, where he meets with the President (guest star Michelle Nolden), who wants to talk about the events of the last two episodes. She doesn't want Division's dealings to overshadow the White House's agenda. Her staffer Evan Danforth (that's former Terminator: The Sarah Connor Chronicles star Richard T. Jones) makes clear to Ryan that he's prepared to wipe Division off the face of the planet if the situation doesn't improve.
Michael and Nikita try to concoct a plan for stopping Markov and replacing him with a double. Birkhoff suggests they get to him at his hotel room before he meets the President. He also admits that Michael, who speaks Russian and has undercover experience, may be the best replacement. Nikita is sent to Markov's hotel and gasses him. He wakes up with Michael telling him that they've placed a grenade in his mouth and that he has three minutes to get out of the room. Once he does, Nikita is there to meet him, ordering him to get in her car.
Elsewhere, Alex confers with Sonya about the mole situation, during which Sonya notices that someone has breached one of Division's internal firewalls. The alert is coming from Medical, and Alex heads there to find Owen. She asks if he's still having problems with his memories, and he confirms that there's been no change. When she confronts him about the server breach, he says that he decided to search the archives, and didn't realize that he was being watched. "If you're worried about her getting into the system, why are you worried about internal traffic?" he retorts, and volunteers to help her look for the traitor.
Unfortunately for them, they narrowly escape an explosion that rocks Medical just minutes later. First Sarin gas, now an exploding oxygen tank - the Medical department is about the least safe place in Division this season. Surveying the wreckage afterward, Owen informs Ryan that "this was planned," and Ryan tells him and Alex to say it was an accident. He also suggests that Alex should be armed as the mole now knows they're looking for him or her.
Birkhoff is busy scanning every little detail about Markov in order for Michael to be the most accurate double. While he's doing that, Michael tells Nikita that he should only be undercover for "a couple of weeks," until he can arrange for "a nice, natural death."