At four years old, Pete is orphaned by a tragic accident and nearly killed while lost deep in the woods. He is saved by a dragon, and the description of what we can expect is very different from the sort of exaggerated and cartoony Elliot from the original film. This time, expect Elliot to be "enormous, 4 stories tall, with wings tucked back against his body and a spiny back with a great tail that looks like it could level the whole forest with a single swipe." He also has a tendency to change color and blend into environments, with his natural colors being green and brown like the forest itself.
The story picks up six years after that opening, when Pete is discovered and brought to Millhaven, a small American town in the Pacific Northwest. There's a bit of Truffaut's The Wild Child in here, and there's a subplot about industrialization and the decimation of our natural resources, and all of it is there in service of a truly heartbreaking story about a little boy and his best friend.