Hollie Hunter, from Livingston, was so startled by the arachnid on her bed that her neighbours presumably thought she'd stumbled upon an armed intruder, or fallen down the stairs or something.
As a good citizen concerned for the welfare of Hollie, the neighbour called the cops, who turned up in two vans at around 10.20pm on Monday (30 August).
Fortunately for Hollie, the officers were able to see the funny side of things - and even got rid of the petrifying eight-legged intruder.
Recounting what exactly went down, the 30-year-old told Edinburgh Evening News: "I'd just spent 40 minutes trying to get rid of a moth to then come back into my bedroom and find a massive spider at the bottom of my bed.
"I'd honestly say it was the size of the palm of my hand.
"I was launching books at it, and when it ran towards me I screamed and started running to different rooms.
"I think I was screaming and crying and making such a racket that my neighbour thought I was being attacked."
When the pension administrator's doorbell rang a few minutes later, she assumed it was her stepdad coming to her aid - but it was the po-po.
She said: "I looked through the peephole and five policemen were standing there.
"I opened my door, and before they could say anything I just cried: 'I'm so sorry there's a spider under my bed and I'm petrified!'"
After establishing that no one but her and the spider were in the flat, officers took mercy on her and decided to detain and release the beast.
Hollie said: "While they still had my bed in the air, the spider strolled out into the hall.
"One of the officers picked it up with his hand and took it outside with him...not without laughing at me."
Hollie subsequently shared the story on Facebook, and her post received 7,000 likes.
She wrote: "Anyone else screaming that bad last night about a spider crawling under their bed and a moth in their room that their neighbours phoned the police...who turned up in two riot vans and ended up lifting your bed to find the spider? NAH JUST ME THEN?
"Never been so mortified in my whole life, soooo glad they saw the funny side and disposed of said spider. Think it's time to seek help for my phobias."
A Police Scotland spokesperson said: "Around 10.20pm on Monday, 30 August, we received a report of a disturbance within a property in Livingston.
"Officers attended and the disturbance was found to have been about a spider being in the house.
"Suitable advice and assistance was provided and the spider was located and removed."
Be interesting to know what that 'suitable advice' was... don't scream like you're being chased by a man with a chainsaw next time you see a spider?