Gate Keepers: Robert Liparulo

This is the third book in the King series. An old man shows up at the house and claims to be the kid's great uncle. He explains he had to move away because the house kept pulling him through portholes on it's own. The kids spend a lot of time "flying" around in the yard which went on entirely too long for me. They find the grandmother in this book and bring her home, dad gets out of jail, grandmother is sucked back into the house, dad, boys, and New character of Uncle Jesse's care provide go to the world of the future and book ends with them being chased by future beings.