Atticus is normally a creature of habit, so when he breaks his routine, Scout and Jem immediately sense there's something up. Why on earth does Atticus need that extension cord and the lightbulb? And where he is going at this hour? Earlier on, the children were curious as to why Atticus was standing outside the house talking to Heck Tate and some other men. Again, this was unusual, and they immediately realized that something was up.

Curiosity eventually gets the better of Scout and Jem—as it often does—and so they head out after dark to find out what's going on. They find Atticus sitting outside the jail house, reading a newspaper by the lightbulb he brought with him. (Ah, so that's what it was for!) But it's still unclear as to why he's sitting there in the first place. It soon becomes apparent that Heck Tate's had word of a Lynch-mob ready to descend on the jailhouse to mete out summary justice to Tom Robinson. Naturally, Atticus doesn't want that to happen, so he's going to do whatever he can to stop his client from being killed. Yet it turns out to be Scout who actually prevents this from happening.