It acts as the continued part of This Book Is Not Good For You, starting just after Cass eats the magic "Time-Travel" chocolate and falls into a coma, searching for her ancestor, the Jester, to find out what the Secret of immortality is, as she recently became the new Secret-Keeper of the Terces Society.
He also tells the story of when he nearly drowned in a jar of mayonnaise, describing how when he was a baby an old pea had gotten stuck in the folds of his thigh, causing him to scream and cry all the time.
One day, however, at a restaurant, a waitress takes him to quiet him, discovers the pea, and washes him out in a very large jar of mayonnaise to get it out.
She sees a young boy stuck in a tree, and tries to rescue him, only to hear him repeatedly shouting the word "Goat!
Confused, the girl walks up to a puddle, only to see that she has no reflection, realizing that she must be invisible, and that the boy was shouting "Ghost," not "Goat."
When the Seer introduce her name as Clara or Cassandra, Cass's memories came back, making her remember about the Magician, the Jester, the Secret etc.
Pietro introduces the idea of tarot cards that has involvement in Cass's coma, which confuses Max-Ernest.
Pietro explains that the Ace of Wands card is upside down, which refers to the fact that the Tuning Fork should be returned to their principal, Mrs. Johnson.
Cass realizes if Mr. Cabbage Face is here, then Lord Pharaoh, the founder of the Midnight Sun (evil alchemists who go murderous lengths to seek immortality) is too.
Cass also realizes that in the Tale of Mr. Cabbage Face, the author got the place where the homunculus stayed in the palace wrong.
At the dungeon, Lord Pharaoh suddenly arrives and bumps into an invisible Cass, causing the Double Monocle to fall off.
Then, Max-Ernest charges into the Emergency Room screaming because he has an "epileptic fit with the combined result of his allergy to vinyl and a cardiac arrest with the effects of white coat syndrome".
At home, Max-Ernest receives an Email from Yo-Yoji telling him that the school Benjamin went to is run by the Midnight Sun, Dr. L being principal.
He trips and Opal catches the monocle and reports Benjamin and Amber to the principal and sends Max-Ernest to the nurse's office.
Max-Ernest uses the monocle to see himself in the mirror, revealing his future self eating massive amounts of chocolate and writing a book.
Max-Ernest makes a very very long talk to Cass, and plays Yo-Yoji's guitar tunes from his pc.
Cass had awoken because of Max-Ernest's speech, Yo-Yoji's heavy metal and the sudden jolt of electric when Benjamin cut the power.
But at 11:35 AM, Glob writes in his blog that when he went down to the river bank where there is smoke because he thought there was a barbecue there, he witnesses the Midnight Sun chanting the word "SECRET" over and over again near a fire with a very bright ball.
The Midnight Sun catches Glob spying and he flees, before hiding in a cave under a hamburger-shaped rock.
At the joust, an armored man called Sir Unknown (Lord Pharaoh) battles Yo-Yoji.
the armored man tells the Master of Arms that he represents Mary Queen of Scots (Ms. Mauvais).
The rest of the Midnight Sun (disguised as guards) flee as Mrs. Johnson demands that the lodestone is returned to her or else the trio will be expelled.
The trio rush to the riverbank mentioned in the blog post and while Max-Ernest and Yo-Yoji rescue Glob, whom eats a lot of Cass's special trail mix, Cass rushes to the mentioned fireplace, where she meets Sir Unknown, whom reveals himself to be Lord Pharaoh, invisible.
Max-Ernest then hears Cass's calls of help and Yo-Yoji comes out, uses a branch from a tree to trip Lord Pharaoh over and hang him upside down.
When she goes home, Melanie finds a scroll with a drawing of Cass on it, which was the one she drew 500 years ago, and she tells her there is a scrap of papyrus stuck on it.
School Library Journal's Caitlyn Walsh called This Isn't What It Looks Like "a witty mystery adventure [...] that is sure to keep listeners smiling".