It's like M. Night and his team of writers thought of a great idea (people ageing quickly) but never managed to come up with a good enough story around it. This does keep the viewer trying to guess the reason for what is happening to the characters, but then the reason/ending is anti-climactic. Another major flaw is the amount of exposition. It's like the script writers were so worried that the viewer wouldn't know what was going on so they needed to explain everything. It comes across as them taking the viewers for chumps.