The Side Passage

You notice the Keeper has become utterly engrossed in a small bug on one of the wine bottles, and take your chance to slip away into the side passage.

You find yourself in a maze of twisty passages, all alike. You can go north, south… GRUE!

THERE’S A GRUE. DON’T PANIC. BUT IT’S A GRUE. Now would be a good time not to be here. You turn to run.

No. I’m not going to eat you. I’ve just finished lunch, in fact.

You stop and look at the grue quizzically. This is not exactly the usual behaviour of a grue.

Honestly. In fact, I heard you puzzling. I have a puzzle for you. It may help you.

This is really not the usual behaviour of a grue. You don’t get any closer, but you wait to see where this is going.

You see this box here on the floor?” The grue indicates a large, old-fashioned chest, with a prominent padlock. “If you can get into it, I’ll give you a clue to one of the Keeper’s puzzles. After all, I hear everything down here.

You step forward cautiously and examine the chest. The padlock is tightly shut, and set to six zeroes. Attached to it is a label, with a diagram of the lock set to 94-15-87, and a haiku:

If this were not closed
A sequence would have been made
How mystifying!

You turn the label over, and see a large question mark in place of the diagram, along with another haiku:

But it is tight closed
Can you find what is inside?
Are you frustrated?

Keeping one eye on the grue, you warily start to consider how to unlock the box.

Enter the password as six digits only.