The chase had been on for half an hour, and still the elusive light bobbed along ahead of them.

Percy Simmons, down in the engine room, had been fully informed by young Ware of what was going on, and he was coaxing his fine machines to their top notch of effort.

“I can’t see anything of her outlines yet, Ralph,” was Harry’s response to Ralph’s interrogation. “She must be a flyer.”

“She’ll have to be to get away from us.”

“Anyhow, it looks like a stern chase.”

“But not necessarily a long one. I haven’t heard of a craft yet that could get away from the River Swallow, at least, in these parts.”

“You mean an earthly craft,” rejoined young Ware, in rather quavery tones.

“Good gracious! What’s got into you? You surely don’t think that the boat we are after is anything but a motor boat like this one, run by men who have a good reason for not wanting us to catch up with them?”

“Um-er, I just had a shiver. A ‘goose walked over my grave.’ My grandmother says that that means that some sort of spirits are about.”

“Rubbish! I thought you were a different sort of a fellow from that, Harry. We’ll have to quit calling you ‘Hardware’ if you are going to be so soft as to think there is anything supernatural about that elusive boat.”