Vacation in the desert
The premise of this novel takes the characters in an ironic direction. For this family, going to a desert is much more relaxing for a vacation than going to California's many beaches. Perhaps this is a symbolic irony pointing to the private nature of the plot, or maybe it is a way of suggesting to the reader that the presence of crowds and people makes the family's problems more intense. The desert is also ironic, because it seems remote, but Raj still manages to find an adventure there.
The ironic hero
To Raj's parents, his disability makes him ineligible in life, at least in many regards. This struggle becomes full blown turmoil when Raj wanders off into the desert, on his own hero's adventure. His parents struggle immensely to keep their hopes up about their son. As much as they want to hope for the best, they aren't confident in his abilities. When he returns home, he is a hero to them, because he has proven himself to be far more competent than they believed.
The subtlety of experience
When Raj comes back, it's just the same old Raj, but there are subtle differences. The prose points to the subtle adjustments that desert wandering has brought to Raj's personality. Now, he is able to refer to his experience, and so his mental calculation is one experience heavier. This shift is subtle, but to his parents, it is night and day—they know him so well, that they clearly notice. Their experience is extreme, but his is subtle.
The coyote
There is a myth in this desert about a clever trickster spirit who appears in the form of a coyote. Although Raj's disappearance seems perfectly explained by the literal facts, the area cannot help but encourage this family to take a more spiritually enlightened stance. In light of this ironic convergence of plot and myth, Raj's journey takes on a sublime aspect. The coyote myth adds a layer of suspense, because the family's experience was admittedly spiritual to them.
Time and place
This family goes through an ironic experience of time and place. Because the desert doesn't really change as fast as other parts of the country, there is a timelessness about the story, and because the place is so different than what they're used to, there is a sense of ambience as well, as if the family stepped out of their lives, out of time itself, to undergo an encounter of wonder and transformation. Of course they are in a specific time and place, but their perception is ironically detached.
