Due to the ingestion of Medusoid Mycelium (possibly)
- "I won't force you."
- —Ishmael's catchphrase
He tells the other colonists on the island that his feet are injured, and keeps them covered in clay to promote this idea (as it supposedly has healing powers), but he is lying so that he does not have to do much work on the island. He does not allow anything to happen on the island that will change the customs and traditions that he has put in place. For example, Miranda Caliban has to learn the backstroke in secrecy, as he claims it is not the customary way to swim.
Although he always tells the islanders "I won't force you," it soon becomes apparent to the Baudelaires that his decisions go largely unquestioned and his suggestions are obeyed like orders anyway.
Ishmael was once a member of the V.F.D. He washed up on the island like everyone else, although there is no detail on what circumstances exactly brought him there. He regards Count Olaf as his personal enemy, blaming him for the act of arson that destroyed his home, although Olaf later refutes this, saying that it wasn't caused by him at all.
Because of his involvement with V.F.D. and the schism, he wanted a life on the island as far from treachery as possible, so after he became the island's facilitator, he made everything on the island simple. The same three dishes were served for breakfast, lunch, and dinner respectively (the dishes were bland). Another example is that he did not allow forks because it can be used as a weapon. The other islanders were kept in a submissive form by insisting that they regularly drink fermented coconut milk, an opiate that keeps them from protesting against his customs. He is responsible for the upkeep of the arboretum and the secret library within, as well as all of the detritus that washes up on the coastal shelf, pulled to the arboretum by the sheep. He predicts the weather with a tall periscope, although he tells the islanders that it's magic. Because he does not allow the islanders near the arboretum, they do not know that the apples on the giant tree dilutes the Medusoid Mycelium poison. He eats them regularly though, as he fears the eventual threat of the fungus. His frequent eating of the hybrid fruit has made him immune to the poison.
Ishmael welcomes the Baudelaires when they arrive on the island. He has a peculiar reaction when he hears the name Baudelaire, implying he knew of them, or their parents, as he was a V.F.D. member. He allows the Baudelaires and Kit Snicket to live with the island on the condition that they must abide by his rules, while Count Olaf is caged.
During The End, the islanders become annoyed with Ishmael's rules and begin to form a mutiny against him. One night, two of the islanders (Finn and Erewhon) sneak out to feed the children and ask them a favor. A group of discontented colonists are planning a mutiny against Ishmael in the morning, and they ask the Baudelaires to go over to the arboretum where all the contraband items are collected and find or make some weapons to use in the rebellion. Further, the mutineers refuse to help Kit unless the Baudelaires help them. The children agree, and set off for the arboretum. The orphans discover a well-appointed living area before they are discovered by Ishmael. They learn that their parents were once the island's leaders and were responsible for many improvements meant to make island-life easier and more pleasant, but they were eventually overthrown by Ishmael, who believed that a strictly-enforced simple life (combined with the opiate of the coconut cordial) was the best way to avoid conflict. The Baudelaires find an enormous history of the island, entitled A Series of Unfortunate Events, written by the many different people who had served as island leaders, including their parents and Ishmael. Ishmael also makes references to many other people, including a girl with only one eyebrow and ear (the mother of Isaac Anwhistle) and Gregor Anwhistle. Ishmael says he learns to drink tea as bitter as wormwood, which, non-coincidentally, is what Kit Snicket says tea should be like. He also says he had a very important conversation with a waiter in a lakeside town.
The Baudelaires and Ishmael go back to the other side of the island, where the mutiny is already underway. Count Olaf returns, still in disguise. After a brief exchange, Ishmael harpoons Olaf in the stomach with a harpoon gun, which shatters the helmet containing the Medusoid Mycelium, infecting the island's entire population at once. The wound later kills Count Olaf.
The Baudelaires find apples as a cure, although the islanders have abandoned the mutiny and boarded their outrigger canoe, ready to set sail. Ishmael refuses to allow the apples onboard, though it is clear that he himself has already eaten one to cure himself, and the boat sails away to a horseradish factory to save everyone (It is hinted that one apple might have been sneaked on board by the Incredibly Deadly Viper to tide them over until they reach the factory). Ishmael also claimed coconut milk could help with the poison, although admits that it's due to the mental comfort.
- "Baudelaires, as your facilitator, allow me to give you a piece of advice, as you begin your stay on this island. Don't rock the boat. We've been living by our customs for quite some time. Most of us can scarcely remember our lives before we became castaways, and there is a whole generation of islanders who have never lived anywhere else. My advice to you is not to ask so many questions or meddle around too much with our customs. We have taken you in, Baudelaires, which is a kindness, and we expect kindness in return. If you keep prying into the affairs of the island, people are going to think you're unkind—just like Friday thought Olaf was unkind. So don't rock the boat. After all, rocking the boat is what got you here in the first place."
- "What do your parents know about surviving?"
- Ishmael regularly asks the islanders to refer to him as Ish, although Count Olaf is the only person that ever calls him that, near to the end of The End. This is an allusion to the famous opening line of Moby Dick, "Call me Ishmael".
- In The Wide Window: Part Two, a taxi driver says "Call me Ishmael", which may be a dual reference to both Moby Dick and The End.