I had Havana syndrome when I was in Santiago de Cuba, those mojitos must have been russian agents.
Archer has to infiltrate a top secret russian lab to find the technology they’re using. Barry finds out and destroys half the lab trying to stop Archer. When he eventually finds the right lab, it’s a kreiger clone working on the device, but he can’t get it to work because they got the idea from the reports of havana syndrome. Back in the US the agency finds out the CIA already know it’s just migraines but are playing up the threat for political reasons, and recall Archer.
Stinger shows the Kreiger clone is just temporarily standing in for actual Kreiger, who says something about it just being a hobby project when asked if trying to make the device counts as treason.