The Medusa survivors have been reduced to five, Peter, the scientist, is dead, but only his laptop survives, holding the files he downloaded and removed about level 4 from the main computer.
Meanwhile, Tim has opened the door to the corridor and let the blond woman, the black man, and Marco through. Marco and Kasumi have rejoined the others. But the effort has exhausted him, and he's fallen asleep. However, the navigator that Marco gave the kid is no longer working, and the Black man, in his anger, throws it away, while the blond woman says they could have fixed it.
The black man, thinking they are doomed, wants to kill Tim now, but the blond woman holds out some kind of hope, and won't let him. Marco tells Kasumi to drop Tim's computer. If Level Four was as easy to understand as a mere file, he wouldn't have had to infiltrate the place. Kasumi apologizes to Peter and leaves the laptop there.
They find an opening into level four, and all of them except for the black man, enter. His leg is injured, and he won't try to make it down the stairs. Marco points out that all of them have little choice but to go on- the blond woman's indicator bracelet has the strip turned completely black, meaning she has about five hours to live. Marco tells her that she treats Tim like an aunt- not a sister. Why? But he doesn't really want to know. He just points out that finding out what happened, and why they were chosen is the best chance for them to be cured of what is wrong with them.
All of them, except the black man, go down into the fourth level. He stays at the top of the stairs, sitting, thinking that they are heading into certain death. Marco is willing to push on without the others, but Kasumi tries to convince the other ones to go. But it's Tim who convinces the blond Woman to come along, saying he wants to find his mother. Even if he doesn't find her down there, he wants to keep searching.
So he and the blond woman join Marco and Kasumi. As they enter Level 4, Marco gives Kasumi and the blond woman guns to protect themselves. But once inside, the door slams shut behind them, trapping them in a circular corridor filled with a swamp and frogs that spit acid and try to kill them, and turrets on the ceiling that shoot bullets. And though this is the back entrance to the level, the corridor to enter the rest of the level is hidden. But can Kasumi and the others kill or pass the frogs and find the entrance to the rest of Level four, or will they die from bullets or drowning in the quickly-flooding corridor? And even if they survive this, what lies beyond?
Another thrilling and intriguing episode in this series. More questions about the characters, and the nature of their disease are piling up, with little to no resolution in sight. But at the same time, your wanting to know exactly what is going on keeps you interested and reading.
And let's face it- the characters are dying. All of them. And the bracelets they are wearing show they have less and less time left. How much time has passed in the world outside and what happened that all these beasts and physical changes happened to the world?
We haven't learned the answers yet, but with every volume, I am more sure that answers are coming. I find this a intriguing and slightly disturbing series, but I want to read (and see) more. Highly recommended.