What were Mad-Eye and Neville talking about after the Unforgivable Curses scene?

Question

I've just been watching Goblet of Fire and after the scene where Moody teaches the students about the Unforgivable Curses, Neville is found staring into a stained glass window, Mad-Eye tells Neville to come with him to talk.

Neville's just been traumatised by Moody performing the Cruciatus curse on the spider. This seems to have disturbed him and he evidently required some comforting. Did they talk about the curse and it's implications, did (not-so-)Moody try to comfort him? Was it something else?

I'm specifically speaking about the below clip:

What were Moody and Neville talking about? Is this covered in the books?

Answer 1

In what is presumably Moody's first one on one conversation with Neville, after he teaches the class about Unforgivable Curses and Neville is visibly upset at the demonstration of the Cruciatus Curse. Neville is that upset because it's the curse that Death Eaters (Bellatrix, Barty Crouch Jr., and Rabastan and Rodolphus Lestrange) used to torture his parents into insanity. So Moody asks Neville to come have tea in his office.

‘It’s all right, sonny,’ he said to Neville. ‘Why don’t you come up to my office? Come on … we can have a cup of tea …’

Neville looked even more frightened at the prospect of tea with Moody. He neither moved nor spoke.

Moody turned his magical eye upon Harry. ‘You all right, are you, Potter?’ ‘Yes,’ said Harry, almost defiantly.

Moody’s blue eye quivered slightly in its socket as it surveyed Harry.

Then he said, ‘You’ve got to know. It seems harsh, maybe, but you’ve got to know. No point pretending … well … come on, Longbottom, I’ve got some books that might interest you.’

Neville looked pleadingly at Harry, Ron and Hermione, but they didn’t say anything, so Neville had no choice but to allow himself to be steered away, one of Moody’s gnarled hands on his shoulder.

‘What was that about?’ said Ron, watching Neville and Moody turn the corner.” - Harry Potter and the Goblet of Fire, Chapter 14 (The Unforgivable Curses)

Later Neville mentioned that Moody lent him a book, and told him that Professor Sprout said he was good at Herbology. They may have discussed other things, such as the Unforgivable Curses or his parents, but if they did Neville didn't mention it, which is possible since he doesn't usually talk about that with his friends.

“Oh yes,’ said Neville, ‘I’m fine, thanks. Just reading this book Professor Moody lent me …’

He held up the book: Magical Mediterranean Water-Plants and Their Properties.

‘Apparently, Professor Sprout told Professor Moody I’m really good at Herbology,’ Neville said. There was a faint note of pride in his voice that Harry had rarely heard there before. ‘He thought I’d like this.” - Harry Potter and the Goblet of Fire, Chapter 14 (The Unforgivable Curses)

Moody may have comforted him, but...

We know Moody was actually Barty Crouch Jr., and he wanted to give Neville the book for a different reason. He wanted Neville to learn about Gillyweed so that he could pass the information along to Harry, to make sure he succeeds in the Second Task and wins the Triwizard Tournament to fall into the Dark Lord's trap. Barty Crouch Jr. was actually one of the Death Eaters who helped torture the Longbottoms into insanity, so it's highly unlikely that he genuinely cared about Neville. In fact, he probably enjoyed scaring him with the Cruciatus Curse, since we know he knows Neville is their son.

Answer 2

Don't disagree with the accepted answer, but it leaves out why Neville was so upset by the Cruciatus curse demonstration to be begin with.

Neville's parents were tortured into insanity by Voldemort's agents using the Cruciatus curse, so it's natural that Neville would be quite disturbed by the demonstration.

In fact, given that we later learn that Moody is actually Barty Crouch at this moment, it raises the question of whether Crouch intentionally terrified Neville in order to give him an excuse to give him the critical Gillyweed book.

Answer 3

WARNING: SPOILER FOR HARRY POTTER AND THE GOBLET OF FIRE.

So basically Neville is disturbed by the Cruciatus Curse, because his parents were tortured to insanity. In Goblet of Fire, "Moody" was actually Barty Crouch using a Polyjuice Potion. Crouch's job was to get Harry Potter to the last stage of the Triwizard Tournament, so he could use the Portkey and see Voldemort, bla bla bla. So he was planning ahead, and making sure Harry knew what he was doing in the first two challenges.

So he gave Neville the book, Magical Mediterranean Water-Plants and Their Properties. This book had information on Gillyweed, which can let you breath underwater. Crouch's plan was for Neville to tell Harry about the Gillyweed, so he would know what to do in the second challenge. In the end, Dobby ended up giving Harry Potter the Gillyweed, but Crouch's plan was for Neville to give it to him. This is what Neville and "Moody" were talking about. "Moody" was just giving Neville the book.