I'm still thinking about this "ping" thing. On the day she disappeared, it appears that someone called Maura Murray's phone from the area of Londonderry, NH.
I wonder if it's possible the person who made this call was the person who rented a property to Maura that night. If you recall, Maura was trying to track down a rental property in the White Mountains for that night -- she had called the Salamons trying to rent their two-bedroom condo but they could not arrange it for her at that time.
Maybe she (or the tandem driver) was able to leave a message with a renter and the ping was them calling her back. That person was not close to the White Mountains but may have had a listed number for the property Maura wanted. They could have called Maura and told her where to pick up the keys.
I wonder if there is still record of rental places along Rt. 112 in which the listed contact lived in Londonderry.
First one to track it down gets 100 master class points.