Spoilers! Come in, spoilers!

I am 112 pages into Gone Girl by Gillian Flynn and I dread picking it up to read more because, um, DREAD. Seems to be what this part of the book is made of. But I am told there is a TWIST! And INTERESTING THINGS HAPPEN! And there were 400 holds on this book and seriously half my coworkers have already read it.

So could someone please just spoil the crap out of it for me so I can decide whether this is a ride I want to be on?

...People who have not read Gone Girl, it apparently has a twisty thrillery plot and I am hoping there will be full, complete, suspense-ruining spoilers in the comments, so consider yourselves warned.