Counter Strike Online Wiki

Rex Labs (zs_biolabs), Missed Connections or Staggered Steps is the third chapter of Zombie Scenario Season 7 in Counter-Strike Online.


After escaping Panic Room, Erica, who was trying to control her body, began to periodically experience unexplained pain. David Black struggles to find the cause, but one day, when there is no way out, he was contacted by Soi. Soi heard news about Erica, and after seeing related information in the lab data, she told him to come to the Rex Labs if she wants to cure Erica. David Black and Erica set out for the Rex Lab after listening to it. But it wasn't Soi that greeted them, but a lab that seemed to have been attacked. Now they start searching the lab for any clues.


Meet with Dr. Soi to resolve Erica's unknown pain.


  • Track and investigate clues along the way and reach the final goal.


  • Play the game through the guide information displayed on the map.
  • Pressing the [E] key in the area marked with [E] activates the indicated device.
  • You can attack and destroy structures that glow red and continue the game.

Release date[]

  • South Korea/China: 4 February 2021.
  • Taiwan/Hong Kong: 8 February 2021.
  • CSN:S: 17 February 2021.


Davidblack msg
Jpngirl01 msg
  • David Black: I'm sure this is the right place for Dr. Soi's lab...
  • Erica: I think the lab was attacked. Maybe I should have kept in touch.
  • David Black: We've been out of touch since she invited us.
  • Erica: We can't reach her and the lab's collapsed. What the hell happened?
  • David Black: I don't know. Maybe there's a message or clue left.
  • Erica: Sure. I can see another door inside. Let's go that way.
Entrance to the institute
  • David Black: But what's this mark? It looks like a palm.
  • Erica: What happened in the lab? That's an ominous sign...
Damaged lobby entrance button
  • David Black: Oh my God. The doorbell's broken.
  • Erica: It's so quiet.
Cargo loader (green)
  • Cargo Loader-G: I'm working. I exist. I'm moving.
  • David Black: Erica, just in case, don't get too close to the robot.
Trigger 3
  • Erica: Oh my! This yellow robot looks cute when it's small.
  • Erica: Cute robot. Why don't you tell us how to get inside?
After inserting coins
  • Cargo Loader-O: Notice. Inserting a coin will work.
  • Cargo Loader-O: Stopping the equipment.
  • Erica: No, you can't...
  • Cargo Loader-O: I'll stop.
  • Erica: Huh? What is it? It's really... stopping.
  • Cargo Loader-O: Human. Unauthorized voice detection. No. Stop.
Trigger 4
  • David Black: Oh...Erica... I felt a sign that this was going to happen. Are you okay?
  • Erica: Ah?... Yes... I'm okay. I need to be careful.
  • David Black: I don't know if there's a connection to the inside as I see the wind coming from this side.
Enter the ventilation system bypass
  • Erica: The wind is so strong that I can't move!
  • David Black: Let's get rid of the fan's propeller shaft!
Trigger 5
  • David Black: They're infected! It wasn't safe here either...
  • Erica: Ahh! More coming!"
  • David Black: Hurry! Stop the fan and evacuate! Come on, use sticky bombs!
Trigger 6
Lobby entry
  • Erica: Ugh... Maybe it's because of the battle, but I think it's getting worse.
  • David Black: Are you getting symptoms again?! Would it be okay to move?!
  • Erica: It's okay. It's not that bad... It'll get better in a minute.
  • David Black: The symptoms seem to come more and more often. We need to see the doctor sooner...
  • David Black: I need to find a place to rest. There must be a rest room inside.
  • Erica: Yeah... We need to clear that bush first to pass.
  • David Black: The inside is not even old, but the bushes are too big. Be careful.
Enter Lab R
  • Erica: Wow! The flowers are so pretty.
  • David Black: Wait! Erica! I think it's better not to touch it.
  • Erica: Phew. I almost got burned.
  • David Black: It's dangerous. We'd better get rid of it.
Enter Long Hall A (Exam tree)
  • David Black: What is this place for...? It's full of strange plants.
  • Erica: It's quite bizarre and creepy. What the hell was she studying?
  • David Black: I know. Why did Soi say you need to come here to heal you...
  • Erica: I'll know when I get in touch. If you look a little further, you'll find something
  • David Black: Yeah, let's cheer up a little bit more.
After leaving Long Hall A
  • David Black: It's blocked...We need to move to another floor by elevator.
Elevator 1 button operation
  • David Black: Back off!! The elevator is crashing!
  • Erica: Argh!!"
  • David Black: Oh my God... We almost got in trouble... Let's find another way.
Access to Lab B
  • Security System: Notice. Only those who have registered biometric information can enter Lab B.
  • David Black: Biometric information...
  • Erica: I can see something through the window!
  • David Black: Is that a biometric information registration device?
  • Erica: The device screen says it's registering a fingerprint or something.
After registration of biometric information
  • Security System: Biometric authentication completed. Please enter after suit and equipment inspection.
Entrance to Lab Area B
  • David Black: Wait! It's dangerous here! There's an electric current on the floor!
  • Erica: The top of the blue pipe looks safe! Come on up here!
  • David Black: Is there a good way to cut off the current at the door?
  • Erica: I think it would be good to spill water that becomes a conductor.
  • David Black: All right. Let's find something to activate the pumps around us.
  • Erica: Where's the valve...
  • Erica: I found it! It's between the flowers. This way!
Enter the ventilation control area
  • David Black: The building is quite complicated. Is there any clue...
  • Erica: What is this place?
  • David Black: The bright light up there looks like a control room. How do I get up there?
  • Erica: Why don't we refer to the operating instructions for the control room we saw earlier?
  • David Black: A small fan and a large fan's current device are connected...
  • Erica: Wouldn't a large fan be overloaded if I break a small fan next to it?
  • David Black: Then let's destroy the fans on the side first.
Operation of large fan on the first floor
  • Erica: The device's on! I think the air volume of a large fan will reach the 2nd floor!!
Enter the fan area on the 2nd floor
  • Erica: Ugh...I'm getting more and more curious about what she's been working on...
  • David Black: Are you okay, Erica?!
  • Erica: I guess it's because I moved too hard. It will be okay if we slow down a little bit.
  • Erica: I think something went wrong since the panic room incident.
  • David Black: If it weren't for the Vanguard Company...
  • David Black: Let's slow down until we find a place to rest.
  • Erica: Yeah. Thank you.
Cargo Loader Event
Water Pump Control Room
  • Cargo Loader-O: They're fighting. Humans. Each other.
  • Cargo Loader-O: Fix it. Robot. Together.
  • Cargo Loader-G: Can't enter. Block. Help.
  • Cargo Loader-G: Find. Bypass. Calculate. Optimal route.
  • Cargo Loader-G: Fire. Crash. Angry people. Electricity. Tree. Flower bouquet. Water. Wind.
  • Cargo Loader-G: Wind! Calculation complete.
Water pump room intake
  • David Black: Ahh!
  • Erica: Argh!
  • Erica: I'm glad you know how to swim..
  • David Black: Okay. That's a relief. How do I get out of here anyway?
  • Erica: I guess the robots are helping us. What did you say earlier!?
  • David Black: Let's not trust the machine too much.
  • Erica: Are these devices that were called drainage devices?
  • David Black: Well. But maybe we should try to get it working just in case.
  • Erica: There's a button up there too!
  • David Black: I'll go up there. Wait a minute.
Enter the corridor to Soi Lab
  • Cargo Loader-O: Human. Help. Each other. Robot. Hungry. Oil.
  • Erica: Oh! Oh my! It's so fast!
  • David Black: These are really weird guys...
Trigger 14
  • David Black: The nearby space must have been used by researchers...
  • David Black: Let's hope Soi left something behind.
  • Erica: Oh...There's no one here
  • Erica: There's a name on this side!
Button in front of Soi Lab door
  • David Black: This is the place. Please have something left...
After Soi Lab Investigation
  • Cargo Loader-O: Working robot. Over-worked. No lubricant supplied.
Trigger 15
  • David Black: Erica! Watch your step! Don't fall!
  • David Black: Stick to the wall as much as you can!
  • Erica: Argh! Something's flying everywhere!
  • David Black: The projectile hits the wall and bounces off. Stick to the wall!!
  • David Black: It's like the flower at the entrance...It looks dangerous, so step back!
  • Erica: Argh!
  • David Black: The railing is at stake. Let's get into the water and prepare for the impact!
  • Erica: It keeps exploding!
  • David Black: We have to stick to the wall! Do not take damage!
Trigger 16
  • David Black: That was close... Did you get hurt, Erica?
  • Erica: Yes. Slightly scorched but I'm fine. Are you okay?
  • David Black: Thanks. Let's get out of here now that we've found a clue.
  • Erica: If we go there, we will be able to meet the doctor, right?
  • David Black: Yeah, sure we will.
  • Erica: Look over there! It looks like a person over there!
Last Surviving Security Officer
  • Security Guard's Notebook: There are people left in the engine room with a door lock.
After checking the engine room
  • David Black: It's too late...
Entrance to Lab O
  • Erica: Are you okay? Was he...?"
  • David Black: He's already dead. I found a message...
  • David Black: I think the exit is dangerous. Let's be careful.
  • Erica: Yeah... Let's cheer up a little bit more!
  • David Black: It's an inflow of contaminated water! Everyone stick to the side wall and move towards the monorail!
Trigger 18
  • Erica: Get on board now!
  • David Black: I hope everything's okay with the last one.
Boss room
Zbs73 msg
  • Security System: Unauthorized personnel detected
  • David Black: Oh my God! Is the security system still working...? I think something's wrong, be careful!
  • Security System: Enable Intruder Removal Protocol
After boss fight
  • Erica: It was a tough battle...
  • David Black: I'm glad you're okay. I found the last place on the controls.
  • David Black: It seems like Dr. Soi was heading for the survivors...
  • David Black: I wish I could meet the doctor there.


Clue 1 Lobby Security PC
  • [Tracking Clue 1-Rex Lab Notice] Conference attendance information
  • Hello. Proud researchers. It is expected that the results of this year's project will be bright. We have prepared a place to share this achievement with the members of the organization.
  • Senior researchers with level 2 or higher in the research complex. I would like to invite you to attend the 10 o'clock conference hall today. Dr. Rex's dream
  • Conference Hall Lobby -Entry code has been issued-
Clue 2 Engineer's Note
  • [Tracking Clue 2 - Engineer's Note] Voltage Load Related Report
  • XX.X.X 9:27 I'm reporting on the voltage control malfunction. Slight cracks were found in the ground above and below the conference hall. We request the closure of the hall in case of possible ground subsidence or deepening cracks.
  • Engineer's Note: I can feel something unusual going on in the lab on the floor around the conference hall... Is it because of the root stem that broke through the walls of the rest room? Just in case, I need to set the voltage shut-off timer...
  • Conference Hall Voltage Controller: - Unblock -
Clue 3 Researcher's Journal
  • Tracking Clue 3 - Researcher's Journal] Research Log 2A7-34
  • XX.X.X 11:32 Dr. Rex is proud of the success of the experiment. But is the result really perfect and flawless? He doesn't care about the opinions of young researchers like us...
  • Researcher's Memo: This reaction is abnormal. There's definitely something wrong with it. The doctor is wrong. I'll take the gun. We have to let them know!!
  • Private lab area: - Security Shutter Opening -
Clue 4 Ventilation Control Room Operation Guidelines
  • [Tracking Clue 4 - Ventilation Control Room Operating Instructions] Ventilation Fan Current Manual Control
  • XX.X.X 13:47 Inform all engineers in the lab. The security system is activated and the ventilation system is out of control. As a temporary measure, manually switch the ventilation fan control method.
  • Manager's Note: What the hell is going on? I don't see anyone in the lab looking normal... It's too early to be frustrated! The ventilation shaft's all in my head!
  • Ventilation Control Room Opening: - Wind direction control for small and large fans -
Clue 5 Drainage Pump Emergency Operation Tips
  • [Tracking Clue 5 - Water Pump System] Emergency Drain Operation Tips
  • XX.X.X 14:05 The in-lab drainage system is operating abnormally due to enhanced security systems. Temporary water outage is expected and restoration will be carried out as soon as possible. We apologize for any inconvenience this may have caused to the staff of the institute.
  • Plumber's Note: Do you think it's normal that the drainage system doesn't flow back in a building with this height? I don't know who built this facility or why. It's annoying and troublesome, but I need to show off my old swimming skills again...
  • Tips for operating the water pump drainage system: - Manual opening and closing of the backflow control pipe at the bottom of the pump room -
Clue 6 Dr.A's Report
  • [Tracking Clue 6 - Dr. A's Record] Rex Lab Threat Outbreak"
  • List of incident progress on XX.X.X
    • 13:30 - My lab's been taken over by outside forces.
    • 14:00 - System paralysis across the research facility
    • 15:00 - Threats of local terrorism throughout the lab
    • 16:00 - Progress in large-scale disturbances and establishment of a plan to gather survivors
  • Dr. Soi's Record: Evacuate all survivors and visitors who discover this. As the emergency security system was strengthened, it was converted into a first-class danger zone. There is still hope for healing and recovery.
  • Announcement of new safety residence: Issue Central Control Room Coordinates: - X: 8032 Y: 7247 Z: 4314 -
Clue 7 Security Officer's Diary
  • [Tracking Clue 7 - Security Guard's Diary] Physical Threat Response Reporting
  • XX.X.X 14:32 External physical threat occured. Security team quickly built defense lines but failed. Sharing of intruder information - The real leader of the hostile forces: Turned out to be 'Jim' and 'Gerard'
  • Security Guard's Note: I never thought Dr. Rex was such a scary man...!
  • Those two young friends outside weren't a threat... They were trying to help us! I hope all agents will absolutely keep in mind that they aren't hostile forces!!
  • Another truth revealed: - Final objective: Evacuate to the central control room -




  • The entrance of Rex Bio Lab is very similar with Black Mesa Research Facility, especially with the train ride and MTM-8 Robotic Loader.
  • Some parts of this chapter resemble Blast Pit chapter in Half-Life. Some other parts resemble Contact.
  • Some models and props are from Poke646: Vendetta, a Half-Life mod.
  • Unlike other main newer Zombie Scenario maps, this chapter has 2 maps only instead of 3.
  • Unlike All-Out and Rendezvous where players need to repair devices to proceed, this chapter does not have such feature.
  • Considering the long gap between this chapter and the previous one (nearly two years), it can be speculated that the chapter and Zombie Scenario story overall have been revamped greatly. The story switched from all-out wars against Kronos to focus on certain characters. The long gap can also be explained due to the launch of Season Pass, which probably take the resources and switch focus of the team. There was also a leak in South Korea patch note, but quickly removed after that, about a Zombie Scenario chapter named "Counterattack" or "Counterstrike", which could be the original name of the chapter.