Adam Scott was given 'creepy' note by Aubrey Plaza while filming Parks and Recreation

If you thought passing notes between each other was something that people left in school, it seems you ought to think again.

It turns out that actress and comedian Aubrey Plaza is still partial to sending her pals covert messages on paper when she's supposed to be busy working.

But according to her Parks and Recreation co-star Adam Scott, her notes aren't for the faint-hearted - as he found out shortly after joining the cast in 2010.

The Step Brothers star, 51, had his first appearance in the NBC comedy in the final two episodes of the second season as a guest star.

However, he proved to be such a hit that he quickly became a main character in Parks and Recreation for the remainder of the show, which eventually wrapped up in 2015.

Seen as though the cast was made up of comedic titans such as Amy Poehler, Nick Offerman, Kathryn Hahn and Billy Eichner, you can imagine Scott probably felt the pressure.

But thankfully, we no longer have to imagine what the Monster-in-Law actor felt in the moment, as he's spilled the beans about it in Jim O’Heirs new book.

Aubrey Plaza gave Adam Scott quite the creepy welcome to the Parks and Recs cast (Colleen Hayes/NBCU Photo Bank/NBCUniversal via Getty Images via Getty Images)

The actor - who is good pals with Scott and played Garry Gergich in the sitcom - will be releasing Welcome to Pawnee: Stories of Friendship, Waffles, and Parks and Recreation in December.

The book looks back on the success of Parks and Recreation and is set to be brimming with hilarious behind-the-scenes stories about the incredible cast.

And one of these is about the 'creepy' gift which Scott received from Plaza when he had just started shooting together.

It explains that the cast had sat down for a table read to run through their scripts, and by the end of it, Scott couldn't help but 'breathe an audible sigh of relief'.

Hey, we've all been there after a nerve-wracking afternoon.

But while he was decompressing after his big day, Plaza decided to approach him with a tightly folded note.

Scott explained: "Do you remember the movie Shutter Island where Leonardo DiCaprio and Mark Ruffalo go to the mental hospital, and I think someone passes them a note?

If you've seen Shutter Island, you'll probably remember this chilling note (Paramount Pictures)

"At the time, it was a famous moment that had just happened in a famous movie," he went on.

I'm sure fans of the 2010 psychological thriller will already be well aware, DiCaprio refers to his notebook and sees the words 'RUN' scribbled beneath his jottings.

So, what do you reckon Plaza did?

Scott continued: "Aubrey’s note said 'Run,' just like in the movie.

"It was a perfect welcome note," he laughed.

Thank god he didn't literally leg it, anyway, as we would have missed out on five seasons of Scott's comedy gold.

And kudos for the prank, Plaza - let's just hope she didn't test it out on any interns.