Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

Ex Input:
What was the reason behind the conversion of human into USB in the movie Lucy?   Why did the heroine change herself into USB when she used 100% of her mind, and then texted the policeman ("I am everywhere")?   She traverses many old eras, and in the end just forms a strange structure, giving the researcher (scientist) USB and then that huge structure falls off?

Ex Output:
Why did Lucy convert herself into a USB?


Ex Input:
As far as I can tell, Phantasm 1, 3, and 4 are only available on DVD. Is there a reason why this is so? I can't tell if the rights are owned by a different company, but I don't believe this to be the case.   And the second movie is hardly such a classic that it would be included in the Criterion Collection or anything like that.   So what gives?

Ex Output:
Why is Phantasm II available on Bluray while the other movies in this series are not?


Ex Input:
I'm a bit confused about a scene in How To Train Your Dragon. When the Vikings reach the nest, they open holes and the dragons are flying away. Why didn't they do that in the first place and wait for the humans?  I mean, they had input/output ability from the nest (they could fly to the village to steal some food). Could it be that the queen kept some dragons as "prisoners" and only a subset of the dragons were going to the village, so that they are doomed to get back in the nest, so that they didn't lose their friends (just a thought, not a clue of this in the movie)?  I was wondering if someone could explain this to me or if it really is a plot hole in the story.

Ex Output:

Why didn't the dragons leave their lair earlier?