Twilight paced in circles around the centre of the room. Three days had passed, and so whoever had left the letter on her desk would presumably get in contact with her again. She just wasn't sure of when that would happen. She'd given everyone working at the lab the day off, pretending she would be cleaning it and doing some maintenance, and she'd actually busied herself with that as she waited for something to happen.
She was nervous. She had questions she wanted to ask to whatever creature had managed to sneak into her castle completely undetected and cut a hole in the wall behind her desk while at it, and she was obviously worried about what someone capable of that might do if ill-intentioned. The lack of any attacks or threats of sorts was a good sign, but still she couldn't perfectly trust them. For all she knew, she could still be walking into a trap, and it was all a way to get to her alone.
But just as with the feather they'd left, if it was a trap she had no other option but to walk into it. They knew too many things she didn't, and she had to get that knowledge out of them. Even if it meant risking her life. She smiled a bit as she thought about that. They could be good with tricks, but it would take more than a little disappearing act for them to take her down if that was the plan.
She brought the letter over in her telekinesis and had another look at it. Still nothing. She'd made other attempts at writing on it, but she'd received no answer. But if she was ever going to get one, it was probably then. So she picked up a quill and wrote on it again, asking for a more definite answer on when the meeting would take place. To her surprise, it only took a short while for words to appear in response. Though the content of those words was perhaps a bit less exciting.
Check again in ten minutes.
Twilight mulled over the sentence for a bit. Then, she shrugged, and went to check on one of the microscopes to pass the time. The ten minutes were almost up when she was done, and she picked up the letter again in her magic, waiting. Soon after, writing began to once again form on its surface.
Check the hallway.
Curious, a little worried, Twilight walked up to the doors and opened them. The hallway seemed to be empty. Pursing her lips, she took a careful step outside. Then another, looking around for any sign of anything. Then a few more, moving deeper in. Then the doors shut behind her.
She immediately turned, and realising what was happening she lit her horn to force the doors open again. She regretted being tricked like that much more than she regretted isolating the various rooms in the castle from teleportation attempts.
She began to pull, only lightly at first, and found resistance, but before she could pull harder a voice spoke from the other side. She could only tell it was probably male by the way it sounded. "See you at the clocks, thirty minutes from now."
Then the doors gave out, and Twilight managed to catch just hints of what looked like the end of a tail disappearing inside a portal before that, too, vanished from sight.