Since October, a mysterious flying object has been seen moving through the skies over the South Island of New Zealand. It looks like a cross between a small plane and a drone, with a series of small rotor blades along each wing that allow it to take off like a helicopter and then fly like a plane. To those on the ground, it has always been unclear whether there was a pilot aboard.

Well, it turns out that the airborne vehicle has been part of a series of “stealth” test flights by a company personally financed by Larry Page, the co-founder of Google and now the chief executive of Google’s parent, Alphabet.

The company, known as Kitty Hawk and run by Sebastian Thrun, who helped start Google’s autonomous car unit as the director of Google X, has been testing a new kind of fully electric, self-piloting flying taxi. This is an altogether different project from the one you might have seen last year in a viral video of a single-pilot recreational aircraft that was being tested over water, and it’s much more ambitious.

Imagine starting a network of autonomous air taxis, as Uber is planning to, but long before Uber actually does. That’s what Mr. Page is trying to do.