Hierarch Kekropus:
The more you know, the more danger you will be in. Because I deemed that only those able to protect themselves against this danger should hear this story, I deliberately chose a dangerous place like the Nornil's Cave. If you were able to enter and exit that place safely, you have proven your ability and earned the right to hear the secret.
Ah, yes -- now that you have been acknowledged by N, you may enter the Nornil's Garden. You may also take your companions. Because they do not all need to necessarily be acknowledged by N, you should be able to form a group fairly easily. It would be safest to enter with a group, if that is possible.
But also know that N will not allow those who have already earned a promotion or are over level 20 into the garden.
Ask why it was necessary to be acknowledged by N in order to enter the Nornil's Garden, and ask who N is.