[user104658]

Originally Posted by Swan

I think they killed her. I'm not sure how or why, but im certain they're responsible for Madeleine's death.

The "occams razor" of the case is that they had drugged the children (probably OTC antihistamines) to keep them asleep so that they could go out and relax and Madeleine sadly either had a bad reaction and died in her sleep, or woke and had some sort of accident (such as a fall). "Why would they cover up an accident/stage an abduction" - because a post mortem would have shown the sedatives.

It's a sad, simple story that aligns with every single piece of the circumstantial evidence.

Crucially, it's blatantly also what the Portuguese authorities at the time believed may have happened.

I doubt we'll ever know for sure, though. Unless one of them tells the full story from their deathbed or something.