I think that it is important to let the reader know the characters of the stories personalities.  The author certainly does this.

                 The most important detail(s) is how the author has allowed you to get to know the characters.  In the story, he he makes it clear that Dr. Shumway is a no-nonsense type of person by the way she acts.  She disapproves of Izadora being with a crook, (she didn't like the fact that Izadora was in a car being driven by an under-age).  And she didn't approve of Izadora beleving in aliens.  (She called it non-sence every time it came up).

Dear readers,

          One of the most important details was Commander Xaafuun and what he/she looked like. Uncle bud or Joe, was the one who said what they looked like, and when it told us about Commander Xaafuun, it said he/she looked like a giant spider[ A.K.A. a tarantula ]. It also said that she had eight eyes, which spiders do, and she was blind in one of them. Stating a fact, lots of us think that Commander Xaafuun may be Dr. Shumwey, or maybe the other way around. I don't think Dr. Shumwey would be Commander Xaafuun because she isn't blind at all, but on the other hand, she could be hiding the rest of the eight eyes. None of us know. Now, back to the answer for the question. Another important detail from the plot was, when Jack was asking for tools while fixing the car, he didn't say any of the right names for them. Isadora suggested using their names, but Jack denied, saying that he doesn't need to. You only need to know what they do. That was important, too, because he was hurrying. He wasn't taking time remembering their names. He had to hurry. He's in danger, and isn't planning on being a slave to Commander Xaafuun.

Sincerely,

Ginny! <3