Fusion Lairs and Infected Zones
Infected zones, their races and top scores, Fusion lairs and their bosses, secret lairs, and how groups enter them together.
Updated 2026-10-17infected zonesfusion lairsracesbossesgroups
Some places are so soaked in Fusion Matter that they are sealed off from the open world. These are the infected zones. Deep inside them, behind portals, are the Fusion lairs where Fuse's copies of the heroes wait. Most nano missions and many story missions end in one.
Infected zones
An infected zone is a separate area you enter through a gate. There are 32 with a race course, from the level 1 KND Training Area in the Future to the level 35 Green Gullet in the Darklands.
Getting in and out
- Each zone has a warp gate with a robot attendant named after the zone, for example KND Training Area. Click the attendant to go in. Leave the same way; most zones have more than one exit.
- There is no entry fee and no level limit. The monsters inside are the real limit.
- Everyone who enters the same zone is in the same place, so you meet other players inside.
- A few entrances are gate-only. Reactor Works in the Nuclear Plant is walled in and can only be reached through its warp bot.
What is inside
- Monsters of the zone's level, usually packed closer together than outside.
- Pools of raw Fusion Matter. Standing in the green goo hurts and keeps hurting for a while after you step out. A nano with an Antidote power protects you.
- Ways around: jump pads, zip lines, slides, moving platforms and launcher cannons. See Vehicles and Transport.
- Services. Every infected zone has a Nano Station and a Power Shopkeeper, so you can swap nanos and buy Power Items, potions and boosts without leaving.
- Recall Points. Click one to register it. A nano with a Recall power brings you back to it from anywhere in that zone.
- A race course run by a SACT Agent.
- Lair portals, often in the hardest corner to reach.
Races, scores and rankings
Talk to the SACT Agent at the start of the course to race. You run to the finish against a clock and collect pods on the way.
- Your score rises with the pods you collect and falls with the time you use. Each zone has a top score that cannot be passed; they are in the table below.
- The result is rated with stars. Fusion Matter is paid for the pods, Race Coins for the stars.
- The rank board keeps your best score for today, this week, this month and all time, next to the best players on that course.
Routes, star thresholds, Race Coins and the race shop are covered in Races.
All infected zones
"Level" is the level of the monsters inside. "Entrance in" is the area where the gate stands.
| Level | Infected zone | Entrance in | Era | Top score |
|---|---|---|---|---|
| 1 | KND Training Area | Sector V | Future | 777 |
| 1 | Pokey Oaks Junior High | Pokey Oaks North | Future | 4,542 |
| 2 | Mandark's House | Genius Grove | Future | 2,611 |
| 3 | Delightful Developments | Peach Creek Estates | Future | 7,373 |
| 4 | Megas' Last Stand | Goat's Junk Yard | Future | 12,684 |
| 5 | Pokey Oaks Junior High | Pokey Oaks North | Past | 11,563 |
| 7 | Mandark's House | Genius Grove | Past | 7,597 |
| 7 | Sweet Revenge | Candy Cove | Past | 4,463 |
| 8 | Delightful Developments | Peach Creek Estates | Past | 7,639 |
| 9 | Megas' Last Stand | Goat's Junk Yard | Past | 15,500 |
| 9 | The Boneyard | Eternal Meadows | Past | 19,598 |
| 11 | Reactor Works | Nuclear Plant | Past | 27,500 |
| 12 | Charles Darwin Middle School | Habitat Homes | Past | 14,500 |
| 13 | Dizzy World | City Point | Past | 17,017 |
| 14 | Sunny Bridges Auditorium | Marquee Row | Past | 12,711 |
| 14 | Jungle Training Area | Mount Blackhead | Past | 10,500 |
| 15 | Loch Mess | Leakey Lake | Past | 8,000 |
| 16 | The Fissure | Townsville Park | Past | 17,895 |
| 17 | Cutts and Bruises Skate Park | Orchid Bay | Past | 9,032 |
| 18 | Sand Castle | Bravo Beach | Past | 27,500 |
| 18 | Crystalline Caverns | Pimpleback Mountains | Past | 11,000 |
| 19 | Construction Site | Morbucks Towers | Past | 24,941 |
| 20 | Hani-Baba Temple | The Ruins | Past | 22,000 |
| 21 | Tyrannical Gardens | Galaxy Gardens | Past | 46,758 |
| 24 | Skypad Space Port | Offworld Plaza | Past | 37,098 |
| 24 | Nowhere Triangle | Area 51.5 | Past | 25,500 |
| 25 | The Canopy | Really Twisted Forest | Past | 32,706 |
| 27 | Monkey Summit | Monkey Mountain | Past | 45,949 |
| 28 | Dinosaur Graveyard | Dinosaur Pass | Past | 20,000 |
| 30 | Inferno Fields | Firepits | Past | 70,835 |
| 32 | Dark Tree Clearing | Dark Glade | Past | 66,000 |
| 35 | Green Gullet | Green Maw | Past | 49,101 |
Two smaller infected areas have no race: the Sweet Revenge in the Future's Candy Cove and the KND Training Ground in Past Sector V. Both are used by early missions.
Fusion lairs
A Fusion lair is a private room behind a portal. The portal is an object named after its lair, for example Fusion Numbuh Two's Lair, and you click it like a warp gate.
- You need the mission. A lair only opens while you are on the mission step that sends you there. Otherwise you read "You are not on the correct mission task for this." Some zones have two portals close together, so check the name before you click.
- It is yours alone. The lair is created for you, or for your group. No other players wander in.
- The boss is a Fusion: a dark copy of a character. Level nano lairs hold the Fusion of that nano's mission, such as Fusion Numbuh Two at level 1 or Fusion Edd at level 8. The list is in Nano Missions.
- Knocked out inside? You get back up at the lair entrance, inside the lair, and can try again.
- Leaving early through the exit, by warping away or by logging out puts the mission back one step. Walk to the portal and enter again.
- After the boss the mission moves on. Lairs without an exit door put you back at the entrance outside by themselves.
Preparing for a lair
- Fill your Nano Potions and Weapon Boosts at the shopkeeper in the zone.
- Equip a nano whose type beats the boss, plus a heal or a Revive - Self nano. See Nanos.
- Clear the small monsters first. Fusions often have Fusion Spawns or other helpers around them.
- If the mission step is timed or has an escort, read it before you enter. Missions explains both.
Secret lairs
Besides the nano lairs there are about 40 secret lairs. They belong to guide missions and world mission chains, not to levelling. Examples are Fusion Dracula's Secret Lair in the Mandark's House infected zone, Fusion Wilt's Secret Lair for the Coop mission, and the three sewers under Townsville Park and the Sunny Bridges Auditorium, which Providence Agents let you into during their missions.
They follow the same rules as any lair: you need the right mission step, the room is private to you and your group, and leaving early repeats the step. World Nano missions such as Scooter Scramble and Cap'n Courageous end in lairs of this kind.
The very last lair is Fuse's own, at the far end of the Darklands. It has three parts: Fuse's Hall, Fuse's Labyrinth and Fuse's Throne.
Going in as a group
Gates and portals take your group with you.
- When a grouped player uses a gate, every group member standing at the gate goes in too.
- For a lair, each member must also be on the same mission step. Members who are not stay outside.
- Inside a lair the group shares one room and one boss.
- Group heals and Revive - Group powers work across the group, which makes bosses much safer.
Level nano lairs can be done alone. A group makes the harder secret lairs of the higher levels much easier. Groups are explained in Groups and Social.
Tips
- Register the Recall Point near a lair portal before you go in. If something goes wrong, the walk back is short.
- Combine a race with the missions that send you into the zone. Both pay Fusion Matter for the same trip.
- A zone's top score is a good target for a race day. See Daily and Weekly Activities.
