The premise was that one twin experienced what the other twin was going through. If one died, the other also died. Until Emmie when all things changed. It engaged my attention start to finish. The end was an unexpected twist in this dystopian novel.
Link to purchase: http://www.amazon.com/Tethered-Twins-Mike-Essex-ebook/dp/B00AWX69S2/ref=sr_1_1?ie=UTF8&qid=1421709256&sr=8-1&keywords=Tethered+Twins