The "it" is the murder of two people as Miles and company are en route to the "Tower" in the Plains Nation aka Colorado. There are suspects galore. Nora was tortured and drugged - who knows what that did to her mind. The guy who did that but then whisked her to freedom - by drugging her so everyone thought he was hauling a dead body - looks a little guilty himself. Meanwhile, Charlie saw Jason talking to some strange guy before the team left Atlanta, right after she kissed him, no less. And Tom, well, he's always suspect.
The only one Miles can totally trust is Charlie, but for some reason he has her put her weapon in the bag too - so no one else can get murdered. I don't get why he had Charlie do this, but ok. But it turns out the killer is - well, just in case you haven't yet seen this episode, I won't tell you. But we get a surprising but logical culprit when it's explained and therefore a good solution to the mystery.
Meanwhile, out at the Tower, we have a situation nearing a boil. In a dramatic last scene, it looks like Rachel pulled the pin on a grenade which will kill her and Monroe. I'm thinking neither will die, but it will be interesting to see how they get out of this next week. And if the power is indeed turned back on, this will make for a very different series next season - a season in which Monroe (if he survives the grenade) won't have the unique power he's had for the second half of this first season.
I'm looking forward to the concluding two episodes and to what season 2 of this excellent series brings.
See also Revolution: Preview Review ... Revolution 1.2: Fast Changes ... Revolution 1.14: Nanites and Jack Bauer ... Revolution 1.15: Major Tom and More 24 ... Revolution 1.16: Feeling a Little Like the Hatch in Lost ... Revolution 1.17: Even Better Nanites