In the evening ,At the School of Friendship Sandbar was walking towards the libary to meet his friends when he overheard some mares talking amongst themselves.
"Cozy Glow baked our class cupcakes today!" The first one (Citrine Spark) said.
"And she made all of us friendship bracelets! "The third one (Patty Peppermint) said,a few seconds later.
"She's the nicest pony I've ever met."The second one said." I'm so glad she's headmare!"
,
"Uh, temporary headmare? Right, guys?" Sandbar said.
" Oh, oh, of course.But if Twilight takes her time coming back, I won't mind." Citrine Spark answered.
All three of them started laughing,Sandbar noticed that Patty started laughing a bit later then the others.The he arrived at the libary and opened the door.
" Finally! We thought you forgot about study club." Silverstream said.
" Sorry I'm late." Sandbar said "Cozy Glow gave our class tickets to a Sapphire Shores concert in Ponyville tonight."
" You get the feeling Cozy's trying too hard to make us like her?" Gallus asked.
" Or maybe she just wants to help us keep our minds off of how scary it is that magic's disappearing."Ocellus said.
All of them nodded in agreement.Then they noticed that Cozy Glow was in the libary too,organizing a few books.
"Why Cozy pony in the libary so late at night?" Yona asked
"Let's go ask her"Gallus said.Before they could approach her,Cozy flew out of the libary towards Twilight's Office and the Young Six started following her.
Meanwhile,Twilight and her friends had reached the gates of Tartarus.
"This is the only door to Tartarus."Twilight said "The good news is the seal isn't broken, so we know Tirek didn't escape."
"Let me guess." Applejack said "You got bad news, too?"
"Last time I was here, I had to use magic to get in." Twilight said "And according to Star Swirl, all unicorn magic was gone by yesterday's sunset."
"Maybe he was wrong." Rainbow Dash said.Twilight tried to open the door but failed.
"Don't worry, Twilight. I got this."Pinkie Pie said,then she knocked on the door."Free pizza delivery!"
After a moment of silence,Pinkie Pie spoke.
"Huh. Always worked before." Pinkie said "Oh, well."
"Did any of y'all pack somethin' that could actually help?" Applejack asked.
"These all do magic, but not the kind we're looking for, I'm afraid."Rarity asked.
"How about this?" Spike asked.
"The Key of Unfettered Entrance!" Twilight exclaimed " Where did you find this, Spike?"
"In your bag." Spike answered "Cozy Glow must've packed it for you."
"She really did think of everything." Twilight said.
"Um, what does it do?" Fluttershy asked.
"It can magically open any door." Twilight said "And since artifacts like this haven't lost their power yet... "
Twilight put the key in then it opened the door.Twilight tried to put it in her bag with her mouth put she accidentally dropped it to the ground and then the key shattered
"Oops" Twilight said as they all got in.The door closed behind them.