Congratulations, Niels, you've escaped the lab dressed as a Russian sailor. Eventually someone's going to do a headcount, or assign you to a job that you have no idea how to do. Or someone's going to say he doesn't recognize you (or worse, someone—say, for example, Admiral Ruskov—does recognize you). Do you even speak Russian? How long do you think you can pull this off?
He's also infected the entire ship just by being in the vicinity of its crew. If the Vrenya can start sailing again (unlikely because the American boarding party took out the drive shafts), this means that there is a very desperate group of armed men roaming the seas.
Coal-fired power plants require a train car full of coal every hour for fuel. Given the societal breakdown from the pandemic, there's no way they could do that logistically because the mines and trains would surely not be operating at anywhere near the necessary capacity. This is the first hint that it's not coal that they're burning in that power plant.
Secretary Rivera and Chief of Staff Shaw cutting Kara out of access to the Oval Office makes sense in light of "Paradise": Rivera was concerned she was putting herself in harm's way by being so pro-Michener (and may have assumed she was adopting such a stance to throw him off the scent since she was the first to discover his body - a possibly suspicious coincidence), and Shaw realized that Kara could not be swayed to her side, and so proceeded to sideline her.
Christos is never shown interacting directly with Lucia or Giorgio, which makes sense when the series reveals that he's a hallucination brought on by Vellek's chronic ingestion of Nostos.
In the opening credits we see someone spraypainting a window in front of the camera. In light of recent episodes, this was very clever foreshadowing of the use of the red X to indicate no-go zones.
Niels Sorenson escapes from the lab disguised as a Russian seaman. If the Vrenya is at all sailworthy, he's just potentially infected the entire ship. In fact, it is implied in the series he did just that before he stole off with a lifeboat, and since then he has been rather gleefully approaching people to see how many he can infect.
As stated above, coal power plants need a steady and abundant supply of fuel in order to provide electricity, leading one to wonder just how many dead bodies were trucked over and how many people were killed with the fake cure in order to make up for the shortages. Amy Granderson is surely going down in history with the title of "Butcher of Baltimore".
Population of Baltimore in 2013: 622,104. 80% (the fatality rate of the virus) is 497,684. Figure 200 people per train car, that gets the plant about 2500 hours of use. Granderson can keep the plant running for 104 days if she goes 24/7, and can justify it by saying she's disposing of bodies that would spread other diseases while also keeping the lights on. She can either clean up surrounding areas (Washington DC is only 40 miles away and has a similar population) or kill off the undesirables among the remaining 20%. Odds are, she's doing both.
Additional note: Amy Granderson apparently did the math and had scheduled power outages planned to prolong the use of the plant. If she only runs it 12 hours a day that's 208 days, or over six months. That's more than enough time she needs to buy to lay her hands on a supply of fossil fuel, likely coal since the Appalachians are nearby.
Possibly even longer than that, since she doesn't have to power all of Baltimore and its suburbs—just the Avocet compound, any other city infrastructure (sewage treatment, water, etc.) that she needs, and a few select neighborhoods.
It is hinted in the series that perhaps the virus was deliberately propagated (leaving Niels Sorenson's foolhardy self-weaponization aside). If so, that explains the rapid rise of people who believe they are "the chosen" because they survived.
With Secretary Michener in the lawful line of succession, the crew of the Nathan James could be forced to follow his orders as the Constitutionally mandated President, even if they know he is being backed by what is, in essentials, an apocalyptic death cult.
Chandler is quick to recognize this and along with Slattery (a former homicide detective who knows how to sweat out a perp) is able to determine that Michener is suffering from acute psychological trauma which made him vulnerable to Ramsay's message. Michener can in fact legitimately be President, but is leaning heavily upon the Nathan James crew to function at the moment.
Shaw's unprincipled ambitions could end up provoking political and economic chaos in the surviving remnants of the United States even as China maneuvers to gain the ascendant in Asia and may have designs on parts of the North American continent later on. Even if Kara and Chandler can expose the coup and put it down, the centrifugal forces unleashed by Oliver's rapid removal of Michener's economic restrictions may prove impossible to reverse.
