Jakob Eilander is a member of the Eilander family, and the eldest son of Caroline and Nicholas. He has returned to Paradise Island, his family's home, after the death of his mother to help with the plagues that have appeared.
In 1796, after receiving a letter from his father, Jakob learns of his mother's death and returns to Paradise, rowing out across Rusty Lake to the island. Even as he returns, the First Plague is already underway and the water of the Lake has turned to leech-infested blood. His entry to the island is blocked by his uncle, Gerard, who demands one shrimp, which is fished up by Jakob's brother David. After finding four leeches and squashing them for their blood, he heads over to the family temple and is confronted by the Corrupted Soul of his mother. She tells him to bring her memories to the Lake in order to stop the plagues. After she disappears, Jakob finds her water-buried coffin and collects one of her memories in the form of a black cube. He puts that cube into a special box and lowers it into a font, returning the memory to the Lake and curing the plague.
He cures the next few plagues in the same fashion, collecting frogs to make stew and using flowers placed by his mother's shrine to lure away the lice. When the Fourth Plague hits, and his brother is transformed into a giant fly-hybrid, Jakob provides him with small animals to drain the blood from. When the livestock becomes diseased from the Fifth Plague, Jakob provides Gerard with a burger made from tainted meat, poisoning him. He then brings him back to life by replacing his heart with clockwork.
When the Lake is frozen during the Seventh Plague, Jakob uses the magic of a powerful snow globe to cause localised hailstorms, destroying the family temple in the process, though the font is still usable for curing the plagues with black cubes. He is the only member of the family to go inside the walls of Paradise during the Eighth Plague, except for his sister Elizabeth, who is not affected by the fog covering the island. After this plague, Jakob is followed by the watchful eyes of an owl, first hiding in the fog as a shadow, but later perching on the remains of his mother in the Ninth Plague. After climbing his way up the island tower, Jakob leads a giant wicker owl to the shore and throws the ground bones of his mother into the ritual bonfire. This leads to the final plague, Death of the Firstborn, where Jakob will be sacrificed. After helping with the preparations, he descends down the font into the Lake, and meets his mother's Soul again. She explains that the last black cube is the final element of the Elixir. Returning back to the surface and entering the wicker owl, he places the black cube down the well. He is burned by his family, who are wearing animal masks. However, he reaches enlightenment, ascending his human form and absorbing his mother's Corrupted Soul to become Mr. Owl.
- In Caroline's memories, the circumstances of Jakob's childhood are slowly revealed. His father Nicholas was preparing him from a young age to be sacrificed as his first-born. However, before Jakob is made to descend into the Lake, Caroline pleads with her husband to sacrifice her instead, and sends her son out on a boat to leave Paradise.
- In Cube Escape: Paradox, it is revealed that he was born in the Winter of 1775.
|Margaret Eilander • Gerard Eilander • Nicholas Eilander • Caroline Eilander • Jakob Eilander • Elizabeth Eilander • David Eilander|