I also think that Voldemort wanted to be the one to kill Harry, and until the spell was done, he wouldn't have been strong or mobile enough to do so.

So why not make just anything a portkey? Why risk his death to make it the TriWizard cup?

I think because of what Nilly said, here, about Portkeys:

However, these don't work in Hogwarts (just like apparating doesn't work there). So they needed to plan a way for Harry to touch one, in a place where Hogwarts' safety spells were drawn off. That's the maze for the third challenge, IIRC. So they had to make sure Harry gets there and gets to the Cup first, because that's the only portkey they could have him touch.

There would have been easier ways, but then there wouldn't have been Harry in Mortal Danger (even before meeting Voldemort, I mean).

Or Dragons.

The safety spells were off for every trial, though. Assuming they never go off campus (do they not, in the book?) it seems that Crouch could have impersonated anyone, got close to him before they even started school, and if not, just make a dragon's egg a portkey and boom!

It seemed way too convoluted as a film's plot.

It seemed way too convoluted as a film's plot.

We just got back from the movie, and I have to agree. I enjoyed it, no question, but it's been a while since I read the book. Except...I don't remember the book's plot pinging me as absurd or too convoluted. I think something got lost in the translation here, because I too walked away thinking, If it was Crouch Jr. the whole time, surely all that was unnecessary?

I mean, I read Nilly's explanation, too, which makes sense, but they clearly didn't explain some things in the movie.

I agree, for a movie plot. I think this movie was very dependent on the book and really didn't work as a stand alone piece, but I'm okay with that.

YokayMV

I think it may have had something to do with getting Harry alone so that Dumbledore wouldn't suspect he'd been Portkeyed off.

I think the movies should absolutely be able to stand alone from the books as a cohesive onscreen unit. Even if it takes director's cuts to do it.

Dumbledore wouldn't suspect he'd been Portkeyed off.

Seeing as they never planned on returning him, it didn't seem a large concern.

Except that they had to ensure that there was enought TIME to do the spell AND kill Harry without anyone noticing him missing from class or whatever.

I haven't gotten the sense from the books that there's any way to trace portkeys, so I'm not sure there's much in the way of time constraints. On the whole, though, I found it a ridiculously convoluted plot in the book, so I wasn't surprised to find it so in the movie.