It was a dark and quiet night.
But then... morning came.
Not just any old morning.
It was the most tiring morning of all. There were no early birds.
It was Adam Carter's birthday.
Everyone else woke up at a fair time before noon, but Mime and Cub were the last ones to wake up.
Adam apparently gave them a very effective sleep medicine.
When 11:00 arrived, Mime and Cub finally woke up.
They were sad when they walked outside. They thought Adam's birthday celebration was already over and they missed it. (Of course, they were wrong.)
(Mime and Cub's thoughts: "Even our dads got to celebrate the fun, but just not us!")
So they decided to give Adam some announcements...
The story starts in the middle of the night, with all of the Happy Tree Friends sleeping. Later, at sunrise, everyone still sleeps. Each character wakes up at a fair time before noon, (Toothy is actually shown doing this), except Mime and Cub. Those two sleep until 11 AM. Then they go outside, thinking Adam's birthday celebration was already over and they missed it. They despair that their fathers may have been at the party without them.
Mime and Cub (but mostly Mime) then give several announcements on the next screen: about Sleeping HTF's last installment of Lumpy, Lammy, Handy and Russell; a planned sleeping-spell story base (that idea was actually dropped, however); and a happy birthday wish. Clicking the green arrow one more time then yields a final birthday message screen.
Above Mime's head is a hidden halo (it only shows up when you move your mouse to the position), and clicking it yields the quiz question, about which official Happy Tree Friends episode has an interaction between the two main characters of the Flash (Mime and Cub). The only such episode is Mime to Five (where Mime ruptures Cub's eardrums). Thus, one must answer with this episode by scrolling the top box to "TV Series", the Season number to 7 and the Episode number to 3, then clicking "Submit Answer." Upon doing so, there is an article explaining some behind-the-scenes of 2016's sleeping Flashes. (Submitting a wrong answer yields an animation of the word "WRONG!" showing up on screen.)
- "It was a dark and quiet night" is a varied version of the parodied phrase "It was a dark and stormy night."
- This animation has been aired before Adam Carter joined deviantART. However, Adam Carter had already told Sleep Mast R that his year of birth is 1997, so he knew he turned 19 in 2016.
- The animations of Mime and Cub sleeping were taken directly from Sleeping HTF.
- The sleeping Toothy is taken from Sleeping HTF.
- Toothy's yawning pose is retraced from Giggles' in I've Got You Under My Skin.
- In the final birthday message screen, the characters on the border are the HTF characters who have shown up sleeping in Sleeping HTF by that point, in order (this Flash came before the last four-character installment). Namely, Cuddles, Toothy, Mime, Petunia and Flaky, Nutty, Cub, Lifty and Shifty, Sniffles and Splendid.
- The music in this flash is Infinite Perspective by Kevin MacLeod.