These two chapters are pretty short and pretty pointless, but I'll give you a quick summary anyway:
Satan makes his face look like a pig's face, because he can, I guess. Then he forces Michelle to watch while an unspecified number of cultists approach the altar. These cultists are all carrying pitchfork-like implements--I don't know why, since they don't actually use them--and a dead baby. They offer the babies to Satan, who tears the bodies to pieces and smears his followers with the blood. Then, since Satan's apparently a greedy bastard who isn't satisfied with just one blood sacrifice, the cultists cart in a teenage girl tied to a large cross, whom he also hacks to bits. Then thirteen women in black come in and offer up "little black bundles," which Satan consumes with fire. We're not told what's in the bundles, and I think we're meant to conclude that they're also dead babies, but I'd like to think that these thirteen women were the only sane, practical Satanists in the group and their offerings were something useful. Maybe a honey-baked ham. I'd demand sacrifices of honey-baked hams if I were a monstrous god of darkness.
This whole baby business, by the way, shows just how unsustainable Satanism as Michelle Remembers describes it would be as a real-life religion. I doubt you can buy dead babies in bulk. Particularly not ones so freshly dead that their blood is still flowing. People who believed in baby-murdering cults seemed to recognize what a big plot hole this was and tried to explain it away with everything from wild stories about Satanic "baby breeders" to scaremongering about abortion, but none of these explanations can possibly account for the sheer number of babies you'd need to keep a giant cult for which a dead baby is an "object as necessary to the proper performance of the Black Mass as bread and wine are to the Catholic Mass" well-supplied enough to operate as we see them operate on the pages. Especially not abortion, since the majority of those are performed well before the "baby" is even recognizable as human.
This chapter shows Dr. Pazder and Michelle taking up progressively more of each others' time (he only sees his other, non-special patients in the mornings now, and she sees him pretty much every day) and then Dr. Pazder has her take an EEG while "remembering" to detect possible anomalies in her brain waves. The neurologist reports that there's nothing at all unusual about the results. Dr. Pazder doesn't quite believe him and sends Michelle to have her skull x-rayed. The x-rays come back negative too.
Then Pazder and Michelle talk about her rash, which hasn't gone away. Michelle says that her dermatologist was surprised she hasn't been treating said rash with anything, which strikes me as a pretty good explanation for why it's not going away. Then there's this:
"Contact dermatitis, mmh? That's what he said?" Dr. Pazder asked. She nodded.
"Well, he's right, of course. It is a contact rash--but how could we ever make him understand that the contact was made twenty-two years ago?"
Michelle smiled. "Or," she said, "that it wasn't a plant I contacted but the tail of Satan."
One, Michelle's making awfully light of her experience here. I know humor can be helpful in coping with trauma, and far be it from me to tell abuse victims how to "properly" react to their abuse, but...well, if I was in her place, I know I wouldn't be acting all cutesy and "tee hee hee, he thinks I got poison ivy when I was actually molested by the Lord of Lies! Isn't that just precious?"
Two, Satan's tail is...pretty sensual. The way it's described and used in the book makes it seem really, really phallic. So a dude rubs his tail all over you, and you then break out in a livid, scabby rash...seriously, Michelle, you're doing no one any favors by leaving your hell-clap untreated. Go and get some penicillin before you pass it on to Dr. Pazder.
Like I said, pointless. Don't worry, things will get exciting (well, about as exciting as you can expect from this book) next chapter.