The first chapter of Chiasmata is titled 'Eukaryote'. It describes the adventures of a girl called Sam Lane, who wakes up in a room without any memory to guide her. It is the first chapter in which four characters are formally introduced.
- A girl awakens in a room that is strange to her. She doesn't remember anything.
- Sam Lane is formally introduced.
- Sam tries interacting with the two wires in the wall of her room...
- when a bolt of electricity...
- solves the puzzle.
- Now she is free, Sam decides to go out and enter the corridor.
- Sam rounds the corner and a second person peeks out.
- Sam remembers that she is from England when she talks to this new person. She comments that they are from Ireland.
- Aidan Byrne is formally introduced.
- Aidan reveals that he can make green, solid things.
- A stone clatters across the floor, startling them both.
- A third person shows their angered face. They appear to be American, and albino. Sam tries talking to them, which goes off a little stiff.
- The existence of the voidwall is revealed.
- Daniel Fleming is formally introduced.
- Daniel continues making rules, but the other two are not very willing to follow them.
- A scream is heard, and the three look into the room, only to be met with a mean-spirited puzzle, resulting in a cut off hand.
- The fourth person is found on the corner, but has two hands. They comment that healing from a cut off hand hurts more than they'd think.
- Bonnie Hallet is formally introduced.
- Upon arriving at the door, the word 'BEGIN?' appears, and later, four puzzles.
- The three are somewhat hesistant about Bonnie's puzzle, which involves her cutting off her arm. Aidan touches it with a bargepole, but nothing happens. Bonnie sighs and goes first.
- Bonnie's side-effect is revealed as her puzzle solves.
- Daniel initially fails his puzzle, but solves it later on, triggering his side-effect in the meantime.
- Aidan goes next, while Daniel and Bonnie argue.
- Aidan's side-effect reveals itself when the puzzle solves.
- Sam finally does a try on her puzzle, and her side-effect sets in.
- The doors open and the chapter ends.