Markus asks Jeremiah and Kurdy to make contact with a group with a view to inviting them to a symposium of allies. The leader of the group proves elusive, but Jeremiah has other things to worry about when he encounters an old flame… and her young son.

Markus is considering planning a meeting to bring together the various groups Thunder Mountain has made contact with recently. One such group is very private; they acquire a lot of material, but then trade it on, acting as a supply line for neighbouring towns, giving them a helping hand towards civilisation in return for food. The control structure is highly concealed, with layers of guards armed with crossbows; even the leader, Steve, turns out to be mythical, with Jeremiah's old lover Michelle the real boss. They have electricity thanks to a hydroelectric dam, and are helping nearby towns experiment with alternative sources of energy such as wind power. Michelle knows of Markus and Thunder Mountain, and is disdainful of their history of inaction.

Anna and Maxine, sisters, were Thunder Mountain pioneers, being among the first to begin reconnaissance a year after the Big Death. The implication is that they were in Thunder Mountain at the time the disease stuck, so they're probably the daughters of a member of the Thunder Mountain staff, or, like Markus, of someone seconded to Thunder Mountain to assist with control of the plague.

Jeremiah and Michelle first met around five years ago; they became lovers, but Michelle left when she realised that their relationship was stagnating her desire to make a better world. It was Michelle who first suggested Jeremiah write and burn letters to his father.

Michelle's son Gabriel (Gabe) is almost five, making it possible that Jeremiah is his father.

Doug, a member of Michelle's group, believes that the group is a waste of time given that Thunder Mountain still has functioning much of the resources that they are striving to learn to build and repair, but rather than blame Thunder Mountain he blames Michelle for her isolationist approach. He also accuses her of misappropriating some of what the group is supposed to receive for her personal benefit. In fact, she is secretly receiving works of art from before the Big Death: worthless, but in her opinion worth preserving. It is Doug who is stealing a share, altering the accounts to point the blame at Michelle.

Jeremiah's brother was named Michael.

Jeremiah to Kurdy: "You know, I had him until you made that 'nipple' comment."

Markus' brief to the team: "Assuming they don't kill you, invite them to join us."

Kurdy breaks an uncomfortable silence: "Look at that: dogs playing poker."

Michelle says "You need to follow the South-West Spur until you get to Colorado Springs". This likely locates her group somewhere near Denver, relatively close to Thunder Mountain.

Michelle's art collection, like the hundred dollar wall (from "To Sail Beyond the Stars") is currently without value, but could become very sought-after should civilisation be re-established.

This is the first episode written by someone other than J. Michael Straczynski or Sam Egan.

Michelle's group's purpose and nature are somewhat different from Markus's, but they're converging. Michelle wants to generate new knowledge of the old methods in topics such as electricity (as Clarefield do, too) but only to assist other, less civilised towns. Interestingly, Michelle says that the fictitious leader "Steve" allows her to go out into the field with impunity. Has Markus ever left Thunder Mountain, and if so, did he feel the need for a second identity? Given her group's trade in information, knowledge of Thunder Mountain and its occupants may not be as limited as has previously been suggested.

Michelle knows Maxine and Anna's real names; but it seems she didn't know they were from Thunder Mountain (given her surprise when Jeremiah and Kurdy mention the place).

Jeremiah and Kurdy like discussing old science fiction films, though they can't always remember the titles.

Markus may well be quite pleased about moving the art collection to Thunder Mountain, after his speech about the Renaissance at the end of "Firewall". An interesting reversal: he said that monasteries kept secular material safe until it was needed again; by contrast, a lot of Michelle's collection appears religious in nature, and is now safe in a very secular, but in some ways very monastic, repository. Add this up with the fact that adults tend to be rather agnostic in Jeremiah, whereas the children have spiritual beliefs and rituals, and one could predict that the next Renaissance could well be a spiritual as much as a humanistic one.

Anna and Maxine are unable to work on the mission with Jeremiah and Kurdy because they are the only remaining contact with this group should anything go wrong. So why don't they split up before the women make their supply drop? They suspect the supply drops are kept under surveillance, but by openly travelling and talking to Jeremiah and Kurdy, they'll just arouse the suspicions of anyone watching when they leave and Jeremiah and Kurdy don't - which is exactly what happens.

Every thriller series at some point does an episode where the hero's old lover turns up out of the blue, waist deep in whatever plot is afoot, with the theme of his or her trustworthiness left to provide much of the story and character development. This could have been a lazy and unsatisfying story; however, by following the structure of "Firewall", interleaving the main story with emotional flashbacks and relying on good performances, this episode manages to remain very enjoyable throughout.