With Cobalion caught, left behind, or conked on the head, it's time to move on to the North and enter Lacunosa Town.  You enter the town from the East, and when you start to head in to explore the place, Juniper and Bianca show up from the North side of town and stop you with a greeting.

Bianca explains that she traveled here using Fly, which is why she arrived before you.  She thanks you for your help in Reversal Mountain, and Professor Juniper informs you that if you pass through Lacunosa to the West, you'll reach Opelucid City.  Before you head out, though, there's something she wants to tell you- you and the younger professor, that is.

Bianca asks what it is, but Juniper just drags the two of you off by way of answer.  After a short trip to the North street you can see from the town entrance, you'll find yourself in front of an old woman, who prepares to tell you 'that old tale about Lacunosa Town'.  She welcomes you into her house, where the three of you have a seat in front of her.

The old woman begins by pointing out that there's a gigantic hole in the ground North of Lacunosa Town- the Giant Chasm.  Bianca points out that there have been reports of random cold temperatures (-58 Fahrenheit) in the Giant Chasm lately- or so she heard from Cheren.  Juniper explains that the road is blocked, presenting an impasse to travel towards the Chasm.

The interruptions done, the old woman explains that the Giant Chasm was created long ago by a huge meteorite that fell from the sky, and a terrifying pokemon was hidden within the meteorite.  Supposedly, this pokemon will appear when darkness covers the land, followed by a freezing wind.  The mysterious pokemon freezes everything and begins devouring people and pokemon.  This is why people were terrified.

Bianca takes a moment to be startled that the pokemon ate people, and the old woman continues.  According to her, walls were built around the town to keep the pokemon out and the inhabitants safe- and a rule was instituted to keep people inside after sundown.

Juniper enthuses about the story, declaring that she will add it to her research notes, then turns to you and says it's time to get going.  The old woman has nothing more to say and there's nothing of interest in her house, so follow Juniper and Bianca outside.