Dozens of fire engines, police cars and ambulances are due to converge outside Xscape at Central Milton Keynes tonight (Tuesday November 19).
But it is nothing to worry about at all, say Bucks Fire and Rescue Service.
A spokesman said: "Please don’t worry if you see emergency service activity outside the Xscape building in Central MK this evening.
"A multi-agency exercise will be taking place to fine-tune our operations and joint working in the event of real emergencies."
Bucks Fire has thanked Xscape bosses for facilitating the exercise.