A possible concise summary is:
Sonic and his friends are stranded on a ship that is attacked by zombies and a giant sea monster. They try to escape, but face many obstacles and dangers. Some of them die, some of them have sex, and some of them make jokes. The ship sinks, but Sonic survives with a few others. Knuckles rides a dolphin. The end.
Here are the key facts from the text:
1. The story begins with Sonic and his friends on a sea Hummer, tired from being out at sea for a long time.
2. The group is running low on gas and is concerned about finding a place to refuel.
3. They encounter a ship called the SS IKEA, captained by Vector, who offers them food and shelter.
4. The group is invited to stay on the ship, but soon discovers that the ship is in trouble and that zombies are on board.
5. The zombies were attracted by dead clones that were on the ship, which had been delivering furniture to IKEA.
6. Dr. Robotnik (also known as Eggman) appears and reveals that he has been tracking Sonic and Knuckles.
7. Knuckles is bitten by a zombie and becomes infected.
8. The group tries to find a way to save Knuckles, but ultimately fails.
9. The ship is sinking, and the group must find a way to escape.
10. Rouge, a character with the ability to control water, helps the group escape by using her powers to navigate through the flooded ship.
11. The group says goodbye to Captain Vector, who chooses to go down with the ship.
12. SPO, a character who had been separated from the group, is found and reunited with them.
13. The group escapes the sinking ship on a small boat.
14. Knuckles, who had been infected by the zombie bite, sacrifices himself to save the others.
15. The story ends with the group riding dolphins and returning to normal.