One seriously injured patient after another arrives at Karolinska University Hospital in Solna on Tuesday afternoon.
The scenario is a state of war and the government has decided to put the country in the highest state of alert.
However, the blood that some patients are covered with is not real blood. Instead, it is about a major exercise that will take place in several places in Stockholm County in the next few days.
This is the Meteor exercise
The exercise, called Meteor, focuses on how collaboration works under difficult circumstances when many units from several authorities have to work together. The health service, the police, the armed forces and the emergency services are all involved.
The exercise will take place during week 46. But exactly where is largely secret, as participating authorities and staff will be tested as much as possible.
This is how it may be seen in Stockholm
For residents, the exercise will be visible through police cars, helicopters, ambulances and other emergency vehicles in several parts of the county.
Blank ammunition is used, which means that loud bangs can be heard both indoors and outdoors in the vicinity of buildings, the police write on their website. People with make-up injuries may be seen in different places in connection with the exercise.
In the clip above, you can see what it looked like at Karolinska in Solna when they received the injured patients on Tuesday.