Flying has its inconveniences, after all, for Johnny could not stop to investigate the injury he had done to Cliff.  He would have to go on, now that he was started, but the thought that he might be flying with a dead man chilled what enthusiasm he had felt for the adventure.

On over the ocean he flew until he had passed the three-mile limit which he hazily believed would bar the planes of the government unless they had express orders to follow him out.  Looking back, he saw that his hunters seemed content to wheel watchfully along the shore line, and presently he banked around and flew north.

From the Mexican line to San Diego is not far—­a matter of twenty miles or so.  Across the mouth of San Diego bay, on the inner shore of which sits the town, North Island stretches itself like a huge alligator lying with its back above water; a long, low, sandy expanse of barrenness that leaves only a narrow inlet between its westernmost tip and the long rocky finger of Point Loma.

Time was when North Island was given over to the gulls and long-billed pelicans, and San Diego valued it chiefly as a natural bulkhead that made the bay a placid harbor where the great combing rollers could not ride.  But other birds came; great, roaring, man-made birds, that rose whirring from its barrenness and startled the gulls until they grew accustomed to the sight and sound of them.  Low houses grew in orderly rows.  More of the giant birds came.  Nowadays the people of San Diego, looking out across the bay, will sometimes look again to make sure whether the sailing object they see is an airplane or only a gull.  In time the gull will flap its wings; the airplane never does.  All through the day the air is filled with them—­gulls and airplanes sharing amicably the island and the air above it.

Up from the south, with her nose pointed determinedly northward and her rudder set steady as the tail of a frozen fish, the Thunder Bird came humming defiantly, flying swift under the moon.  Over San Diego bay, watching through night-glasses the outlaw bird, the two scouting planes dipped steeply toward their nesting place on North Island.  Three planes were up with students making practice flights and doing acrobatics by moonlight.  These saw one scout go down and land, saw the other circle over the field and climb higher, bearing off toward the mainland to see what the outlaw plane would do.

The Thunder Bird swung on over the island, banked and came back over Point Loma, heading straight for the heart of the flying station.  She was past the finlike reef where the pelicans foregather, when the searchlight brushed its white light over that way, seeking her like a groping finger; found her and transfixed her sternly with its pitiless glare.

There was no hiding from that piercing gaze, no possibility of pretending that she was a government plane and flying lawfully there.  For straight across her middle, from wing-tip to wing-tip, still blazoned THE THUNDER BIRD in letters as bold and black as Bland’s brush and a quart of carriage paint could make them.