What an ending!
In these chapters, we really see the line between what is real, and what isn’t, really start to blur. Ricks interactions with the Andy’s leads to what could possibly be a psychotic episode, and eventually becoming unable to notice what is real and what isn’t. We also see some very human actions from the Andy’s.
A very interesting interaction i found was after Rick finished with the Andy’s. He comes home to find his new goat has been killed by Rachael. After Rick finishes talking with Rachael after their night together, she says to him  that he he loves his goat more than his wife. To see a cold machine that normally doesn’t show these kind of emotions do something like this is very human. While this probably was done as payback for failing at her job to convert Rick, this is an action that would normally be seen in a jilted lover. Either way, it isn’t very robot-like.
While waiting for Deckard to come find them, we see how the Andy’s treat animals. In chapter 18, we see John find a spider and the mutilation of it by the remaining Andy trio. When John is confronted by Deckard, Rick tells him that “Androids do that.” One of the major themes of this book is empathy. There are many arguments about how the androids show more empathy than humans, but in chapter 19, we really see how unlike us they really are. They are capable of blending in pretty well, but given the chance, you can see how vicious they can be.
Something else that i found interesting, and i had to go back and check it, is that we finally get a description of Ricks appearance.  When Isodore sees him in the irregular light, he describes him as a “medium man, not impressive; like a clerk in a bureaucratic office.” In the opening scene of the book, Iran refers to to rick as a murderer and to “get his crude cops hands away.” Throughout reading the book, you can’t help of thinking of Rick as kind of a tough guy, like your typical action movie star. Instead he just sounds like a normal guy. It also shows how Rick isn’t your typical hero. He has emotional problems just like most people, something that oftentimes, authors choose to ignore when writing their protagonists.
Once Rick has retired all of the Andy’s, he heads home. He sees that his goat has been killed, and Rick gets in his vehicle and just drives. He ends up in the desert and there is a scene in which he begins to emulate Mercer. I had some problems understanding this scene as like many other novels by Phillip K. Dick, there is generally some altering of reality and the characters perception of reality. He comes back to reality and goes back to his car and opens a new tin of snuff.  When i read that word, i generally think of some sort of drug, and i wonder if maybe the reason he needed a new tin was due to him using it too often? Could this have been part of what lead to this episode? When he discovers the toad in the desert, it is sort of a reset for Rick. Throughout the book, we watch as he became more empathetic towards the “electric” and now we see him fall back into his old ways, thinking about the fame he would receive from the find. When he discovers that the toad is not real, i think he realizes that what he perceives as real and what isn’t, has vastly changed.
The book ends on an interesting note. The book opens with Iran, and it ends with her. Of all the characters, she probably shows the greatest change. As Rick sleeps, she sets in motion the plan to make the toad Ricks pet, ordering food and finding out what is needed for it to function properly. At this point it seems that they’ve switched roles since the opening scene, with Rick being a bit depressed, and her doing whatever she can do to make sure he recovers. It seems that all she needed to get out of her depression was some sort of purpose in life, and helping Rick to recover seems to be that purpose.
Chapter 17, Pg. 202, 1st paragraph
Chapter 19, Pg. 218, paragraph 6
Chapter 19, Pg. 218, paragraph 7
Chapter 1, Pg. 3, last paragraph
Chapter 21, Pg 213, last paragraph