A mysterious "gun" drama left Bricket Wood residents terrified in their homes this week - fortunately Jack Bauer was there to save the day.
People living in Bricket Wood and Garston were shocked out their beds by what sounded like a burst of "gunshot type noises".
Loud explosions could be heard for about an hour and a half through the early hours of Monday morning.
Shortly before 3.30am, one resident reported: "Living near Bricket Wood area close to Garston.
"Hearing loud explosive/gunshot type noises for an hour and a half.
"Very scared/nervous at what these may be?"
On Twitter, John Madden said: "Automatic gunfire Bricket Wood area St Albans. Any ideas what’s going on?"
Another resident called the police.
Officers raced to the source of the shots at the Building Research Establishment, on Bucknalls Lane, but found the shooters armed with film cameras rather than guns.
Sarah Spence, spokeswoman for Hertfordshire Constabulary, said they had not been informed filming would be taking place on the night in question.
She said: "We were called at around 2am to reports of gun fire being heard in the Bricket Wood area.
"Officers were in attendance. However, there was no incident.
"It was confirmed some sort of filming was taking place. Normally, we would be contacted to say filming would be happening in the area."
The noises reportedly continued until 4am.
20th Century Fox Television UK was filming the TV drama series 24.
The scenes shot that morning involved a staged car crash and a few of the main characters having a gun battle on the street with the Building Research Establishment.
However, some savvy Jack Bauer fans marched out to the set to see if they could catch sight of their hero in action.
Helen Wilcock tweeted from the set gate: "We have found the 24 set in Bricket Wood and are hoping to see Jack in action!"
Some residents had received letters from the production company warning them of the night shoot.
The 24 team has been filming scenes across London and in Southampton for the new 24: Live Another Day. The current series of the popular drama is showing on Sky 1.