Why Is the Harbor Inn door locked in Canalave City? (Diamond/Pearl pokemon)?

Question

I need help, I want to see why it's locked, I s there somthing interesting???

Answer 1

its the darkrai event

you have to buy the key for it

Answer 2

You need a membership card. A special item you can only get via nintendo events but I doubt they will ever give it away.

Spoilers:

In the building is a guy he tells you to rest, you fall asleep you wake up on an island and you can catch darkrai.