The nanites saved Danny, and motivated Rachel not to want the light backs on, because that could kill the nanites and Danny. Last week, her leg was badly damaged. There's no way she can travel with Aaron, and he's unwilling to leave her. So Rachel comes up with an wild idea this week ...
Maybe the nanite device, which she took from Danny's body after he died, after the device had kept him alive by keeping his ravaged lung tissue in good repair, could be inserted into Rachel's leg to heal her grievous wound. The very possibility teaches us something about this wondrous technology: it may not be be organ-specific. Possibly it can heal any part of the body.
The fact that Rachel even thinks of this shows that's likely the way the nanite device was intended, and, sure enough, in a great healing scene, it works. Rachel's leg is pretty much all better.
The episode now nicely pivots from the science fictional to the ethical dimension. A local's son has been badly hurt. He comes upon the last of Rachel's super-quick healing and hopes that perhaps she and Aaron can help his son. This would require taking the nanite tech out of Rachel's leg and putting it into the badly injured boy.
Which raises another interesting science fictional question: Presumably the nanites had to continue to work in Danny's lungs because, if removed, his illness would reassert itself. But Rachel's leg was hurt in a physical encounter. Her injuries were not the result of illness. So maybe, having done its work, the nanite device could be taken from her and put in someone else's body to do its good work there.
That's what Aaron hopes to find out. But Rachel, physically all better now, will have none of it. So in a powerful scene she puts it to Aaron that she'll now go on to the tower without him. Too bad - I wanted to see more about the extent of the nanite healing power. Maybe we will next week or next season.
Meanwhile, there were at least two other excellent stories. One features Major Tom saving his wounded son Jason, while Nora risks her life to help Miles save Charlie, and ends up captured by Monroe. Fine, fast combat and powerful family relationships. And Monroe, well on his way to becoming a total paranoid, kills one his loyal supporters after Monroe is almost killed and the supporter sure looks guilty.
Revolution continues to provide riveting, intelligent television, and I'm looking forward to more.