Fire Department Monte ride-on trick

There are three firefighters on the table. Unfortunately, you had to move out so quickly because a house was on fire that you forgot to turn on the siren and flashing lights in the depot.

Luckily one of the firefighters has a horn with him. Press the three firefighters on the helmet. Nothing happens with the left one, neither with the right one, but with the middle one it honks!

Now rearrange the characters and ask the audience to remember where the honking fireman is. The viewers miss each time. But the attentive spectators don't miss the fact that they keep their hands behind their backs every now and then when the horn honks. So your secret is out...

...but if you take the horn out from behind your back and give it to a spectator, it will remain silent...

You will receive the three firemen, an extra horn and German instructions.