This challenge was part of 2020's qualifiers. It's completely self-contained and thus still solvable. But, if you don't mind the spoilers, check the write-up for the complete solution.
After weeks of intense activity, one would expect this to be an opportunity to relax and collect some easy points. Instead, you'll be invited to accept a strange mission…
This time, all you need to figure out what to submit as your final answer will be handed to you all at once, and there isn't anywhere to go except, perhaps, down the rabbit hole.
When you're ready, have a close look at these three images:
At first, each image is meant to be solved separately and in whatever order you like. But, as you'll quickly discover, their solutions are mere parts of a deeper puzzle…
This mission is measured in time — you'll be scored by how fast you complete it.
The final answer will be clear and unambiguous. If at any moment you find yourself wondering if you already have it, then you can rest assured you most certainly do not.
Clues are single use. If you find a clue and use it to figure out something else, you can discard it from your inventory. It won't be needed again.
If you're stuck, consider if you already saw something that seemed peculiar or out of place. Those things have a tendency to be clues, for something.
In the underground, be careful about macOS. It may destroy what it touches.
Submit your answer using the form below. The quizmaster will look into all the answers periodically, so come back in a while to see if your answer was accepted.