This was a bit of a weird story. So, by diverting calls around the worldwide telephone network in a certain way, people figured out how to send the telephone calls into the past. One could even make a telephone call into the future (so I guess they figured out how to do that too).
I found this story incomplete. Sure, it ended abruptly, but that wasn’t the problem. Or was it? I didn’t feel the premise was really set up well enough for the ending it got. But I guess there would be no explanation, really.
An interesting concept, but I would have liked there to be a bit more to it.