You're a noob who just bought the game, you collect some wood, make a table, craft a pick-axe, and mine some stone for a pick-axe, while looking for iron you stumble upon a giant structure, you explore through it, find a chest that contains a weird eye item, then stumble upon a portal, with no second thinking intrigued by the unknown you jump in. You spawn in a weird box, surrounded by "end stone" as you find out by mining it and building upward, you reach the top and are met with a barren land with purple skies and tall obsidian pillars that pierced the heavens, suddenly you are grabbed by a giant scaly hand and pulled upwards, you are met face to face to the final boss, she has already fattened herself up on the poor victims that tried to take her down, and you're next.

Or... so you thought, turns out she's actually pretty nice! and she wants to give you something for braving such a dangerous journey despite being new.