It's a lot like the Time Traveler game you just played. Let's try it out with a pair of pretend twins, Al and Bert, both of whom are 10 years old in their highly futuristic universe. Al's parents ...

First there was Audrey Niffenegger's 2003 novel The Time Traveler's Wife. Then there was the 2009 film adaptation starring Rachel McAdams and Eric Bana. Now, Doctor Who and Sherlock showrunner ...